I.O.F. Chargemen Mechanical Online Mega Test

1. The word HTTP is stand for

Hyper text transfer protocal

Hyper text transfer point

Hyper text tabulated programm

None of the above

The correct answer is "hyper text transfer protocol." HTTP stands for Hyper Text Transfer Protocol, which is a protocol used for transmitting hypertext over the internet. It is the foundation of data communication for the World Wide Web.

Explanation

The correct answer is "hyper text transfer protocol." HTTP stands for Hyper Text Transfer Protocol, which is a protocol used for transmitting hypertext over the internet. It is the foundation of data communication for the World Wide Web.

2. Amit, Sumit and Puneet share an amount of Rs. 660 in the ratio of 3:4:5 what is the share of Puneet

Rs. 375

Rs. 275

Rs. 575

Rs. 675

In the given question, the total ratio of the amount shared by Amit, Sumit, and Puneet is 3+4+5=12. Puneet's share is 5 out of 12 parts. To find Puneet's share, we divide Rs. 660 in the ratio of 5:12. The calculation is (5/12) * 660 = Rs. 275. Therefore, Puneet's share is Rs. 275.

Explanation

In the given question, the total ratio of the amount shared by Amit, Sumit, and Puneet is 3+4+5=12. Puneet's share is 5 out of 12 parts. To find Puneet's share, we divide Rs. 660 in the ratio of 5:12. The calculation is (5/12) * 660 = Rs. 275. Therefore, Puneet's share is Rs. 275.

3. DCXW FEVU HGTS ?

LKPQ

ABZ

JIRQ

LMRS

The given pattern in the question is that each letter in the first group is shifted one position forward in the alphabet to get the corresponding letter in the second group. Similarly, each letter in the second group is shifted one position forward in the alphabet to get the corresponding letter in the third group. Following this pattern, the letter 'D' in the first group would be shifted one position forward to get 'E' in the second group. Continuing this pattern, the missing fourth group would be 'JIRQ', as each letter in the third group would be shifted one position forward in the alphabet.

Explanation

The given pattern in the question is that each letter in the first group is shifted one position forward in the alphabet to get the corresponding letter in the second group. Similarly, each letter in the second group is shifted one position forward in the alphabet to get the corresponding letter in the third group. Following this pattern, the letter 'D' in the first group would be shifted one position forward to get 'E' in the second group. Continuing this pattern, the missing fourth group would be 'JIRQ', as each letter in the third group would be shifted one position forward in the alphabet.

4. Which one of the Equipments used to Transform Mechanical energy into Electrical energy

Electric motor

Dynamo

Mechanical Engine

Loudspeaker

A dynamo is a device that converts mechanical energy into electrical energy. It consists of a rotating coil of wire, called an armature, inside a magnetic field. When the armature rotates, it cuts through the magnetic field, inducing an electric current in the wire. This current can be used to power electrical devices or stored in batteries. In contrast, an electric motor converts electrical energy into mechanical energy, a mechanical engine converts chemical energy into mechanical energy, and a loudspeaker converts electrical energy into sound energy. Therefore, the correct answer is Dynamo.

Explanation

A dynamo is a device that converts mechanical energy into electrical energy. It consists of a rotating coil of wire, called an armature, inside a magnetic field. When the armature rotates, it cuts through the magnetic field, inducing an electric current in the wire. This current can be used to power electrical devices or stored in batteries. In contrast, an electric motor converts electrical energy into mechanical energy, a mechanical engine converts chemical energy into mechanical energy, and a loudspeaker converts electrical energy into sound energy. Therefore, the correct answer is Dynamo.

5. What is the value of Escape Velocity from the Earth Surface

11.2 km/s

2.4 km/s

1.732 km/s

22.4 km/s

The value of escape velocity from the Earth's surface is 11.2 km/s. Escape velocity is the minimum velocity an object needs to escape the gravitational pull of a planet or celestial body. In this case, it refers to the speed required for an object to completely leave Earth's gravitational field. At 11.2 km/s, an object would have enough kinetic energy to overcome Earth's gravitational force and not be pulled back down.

Explanation

The value of escape velocity from the Earth's surface is 11.2 km/s. Escape velocity is the minimum velocity an object needs to escape the gravitational pull of a planet or celestial body. In this case, it refers to the speed required for an object to completely leave Earth's gravitational field. At 11.2 km/s, an object would have enough kinetic energy to overcome Earth's gravitational force and not be pulled back down.

6. A Dynameter is a device used for the measurement of

Chip thickness ratio

Forces during metal cutting

Wear of the cutting tool

Deflection of cutting tool

A Dynameter is a device used to measure the forces that occur during metal cutting. This device helps in analyzing and understanding the forces that act on the cutting tool and the workpiece during the cutting process. By measuring these forces, it becomes possible to optimize the cutting parameters and improve the efficiency and quality of the cutting operation.

Explanation

A Dynameter is a device used to measure the forces that occur during metal cutting. This device helps in analyzing and understanding the forces that act on the cutting tool and the workpiece during the cutting process. By measuring these forces, it becomes possible to optimize the cutting parameters and improve the efficiency and quality of the cutting operation.

7. Which one of the ountry is the largest producer of Gold

Australiya

South africa

USA

England

South Africa is the correct answer because it is the largest producer of gold in the world. The country has been a major player in the gold industry for many years and has significant gold reserves. South Africa's gold production is attributed to its rich mineral deposits and well-established mining infrastructure. The country's gold mining industry contributes significantly to its economy and has made South Africa a global leader in gold production.

Explanation

South Africa is the correct answer because it is the largest producer of gold in the world. The country has been a major player in the gold industry for many years and has significant gold reserves. South Africa's gold production is attributed to its rich mineral deposits and well-established mining infrastructure. The country's gold mining industry contributes significantly to its economy and has made South Africa a global leader in gold production.

8. Find the least number which being divided by 9, 12, 16, and 30 leaves in each case a remainder 3 ?

623

723

728

None of the above

The correct answer is 723 because it is the smallest number that, when divided by 9, 12, 16, and 30, leaves a remainder of 3 in each case.

Explanation

The correct answer is 723 because it is the smallest number that, when divided by 9, 12, 16, and 30, leaves a remainder of 3 in each case.

9. A man sold 250 chairs and and had a gain equal to selling price of 50 chairs. His profit percent is:

5%

10%

25%

50%

The man sold 250 chairs and had a gain equal to the selling price of 50 chairs. This means that the selling price of 50 chairs is equal to the cost price of 250 chairs. Therefore, the profit made by selling 250 chairs is 50 chairs. To find the profit percentage, we need to calculate the profit as a percentage of the cost price. Since the profit is 50 chairs and the cost price is 250 chairs, the profit percentage is (50/250) * 100 = 20%. Therefore, the answer of 25% is incorrect.

Explanation

The man sold 250 chairs and had a gain equal to the selling price of 50 chairs. This means that the selling price of 50 chairs is equal to the cost price of 250 chairs. Therefore, the profit made by selling 250 chairs is 50 chairs. To find the profit percentage, we need to calculate the profit as a percentage of the cost price. Since the profit is 50 chairs and the cost price is 250 chairs, the profit percentage is (50/250) * 100 = 20%. Therefore, the answer of 25% is incorrect.

10. Kinamatic Viscosity is Given by

Dynamic Viscosity/ Density

Product of dynamic viscosity and density

Density/dynamic viscosity

Dynamic Viscosity /momentum

The correct answer is "dynamic Viscosity/ Density". This is because kinematic viscosity is defined as the ratio of dynamic viscosity (a measure of a fluid's resistance to flow) to density (a measure of a fluid's mass per unit volume). Therefore, the kinematic viscosity is calculated by dividing the dynamic viscosity by the density.

Explanation

The correct answer is "dynamic Viscosity/ Density". This is because kinematic viscosity is defined as the ratio of dynamic viscosity (a measure of a fluid's resistance to flow) to density (a measure of a fluid's mass per unit volume). Therefore, the kinematic viscosity is calculated by dividing the dynamic viscosity by the density.

11. Specific Heat is the amount of heat required to raise the temperature

By unit degree of substance

By unit degree of a unit mass

Of a unit mass by 10

None of the above

The specific heat is a measure of how much heat energy is needed to raise the temperature of a given amount of substance by one degree. It is expressed as the amount of heat required per unit degree of a unit mass of the substance. This means that it takes a certain amount of heat energy to increase the temperature of one unit of mass of the substance by one degree. Therefore, the correct answer is "by unit degree of a unit mass."

Explanation

The specific heat is a measure of how much heat energy is needed to raise the temperature of a given amount of substance by one degree. It is expressed as the amount of heat required per unit degree of a unit mass of the substance. This means that it takes a certain amount of heat energy to increase the temperature of one unit of mass of the substance by one degree. Therefore, the correct answer is "by unit degree of a unit mass."

12. After an increment of 7 in both the numerator and denominator, a fraction change to 3:4 . Find the orinal fraction

Numerator : 5, Denominator : 12

Numerator : 7, Denominator : 9

Numerator : 2 , Denominator : 5

Numerator : 3 , Denominator : 8

If we increment both the numerator and denominator of a fraction by the same value, the ratio between the numerator and denominator remains the same. In this case, the original fraction has a ratio of 5:12. When we increment both the numerator and denominator by 7, the new fraction has a ratio of 12:19. However, none of the given options match this ratio. Therefore, the correct answer is not available.

Explanation

If we increment both the numerator and denominator of a fraction by the same value, the ratio between the numerator and denominator remains the same. In this case, the original fraction has a ratio of 5:12. When we increment both the numerator and denominator by 7, the new fraction has a ratio of 12:19. However, none of the given options match this ratio. Therefore, the correct answer is not available.

13. The Detective agency "Research and analysis wing" is the intelligence agency of

USA

Australia

India

United Kingdom

The correct answer is India because the detective agency "Research and Analysis Wing" is commonly known as RAW, which is the primary foreign intelligence agency of India. It is responsible for gathering and analyzing intelligence information from foreign countries to assist in national security and foreign policy decision-making. RAW plays a crucial role in safeguarding India's interests and ensuring the country's security.

Explanation

The correct answer is India because the detective agency "Research and Analysis Wing" is commonly known as RAW, which is the primary foreign intelligence agency of India. It is responsible for gathering and analyzing intelligence information from foreign countries to assist in national security and foreign policy decision-making. RAW plays a crucial role in safeguarding India's interests and ensuring the country's security.

14. A men is facing north-west. He turns 90 degree in the clockwise direction and then 135 degree in the anticlockwise direction. Which direction is he facing Now. ?

East

West

North

South

After turning 90 degrees in the clockwise direction, the man will be facing north. Then, when he turns 135 degrees in the anticlockwise direction, he will be facing west. Therefore, the direction he is facing now is west.

Explanation

After turning 90 degrees in the clockwise direction, the man will be facing north. Then, when he turns 135 degrees in the anticlockwise direction, he will be facing west. Therefore, the direction he is facing now is west.

15. By Doping impurities. The electrical conductivity of semiconducter is

Increase

Decrease

Remains same

Not of the above

The electrical conductivity of a semiconductor can be increased by doping impurities. Doping refers to the intentional introduction of impurities into a semiconductor material to alter its electrical properties. By adding impurities, additional charge carriers are introduced, either by creating extra electrons (n-type doping) or by creating electron deficiencies called "holes" (p-type doping). These extra charge carriers increase the electrical conductivity of the semiconductor, allowing it to conduct electricity more effectively. Therefore, the correct answer is "increase".

Explanation

The electrical conductivity of a semiconductor can be increased by doping impurities. Doping refers to the intentional introduction of impurities into a semiconductor material to alter its electrical properties. By adding impurities, additional charge carriers are introduced, either by creating extra electrons (n-type doping) or by creating electron deficiencies called "holes" (p-type doping). These extra charge carriers increase the electrical conductivity of the semiconductor, allowing it to conduct electricity more effectively. Therefore, the correct answer is "increase".

16. Process of reducing ore with carbon in the presence of flux is called

Quenching

Smelting

Shaping

None of the above

Smelting is the correct answer because it refers to the process of reducing ore with carbon in the presence of flux. This process involves heating the ore with carbon, such as charcoal or coke, in a furnace to extract the desired metal. The carbon acts as a reducing agent, combining with the oxygen in the ore to form carbon dioxide and leaving behind the metal. Flux, such as limestone or silica, is added to the furnace to remove impurities and help facilitate the smelting process. Therefore, smelting accurately describes the process of reducing ore with carbon in the presence of flux.

Explanation

Smelting is the correct answer because it refers to the process of reducing ore with carbon in the presence of flux. This process involves heating the ore with carbon, such as charcoal or coke, in a furnace to extract the desired metal. The carbon acts as a reducing agent, combining with the oxygen in the ore to form carbon dioxide and leaving behind the metal. Flux, such as limestone or silica, is added to the furnace to remove impurities and help facilitate the smelting process. Therefore, smelting accurately describes the process of reducing ore with carbon in the presence of flux.

17. In turning of slender rods, it is necessory to keep the transverse force minimium mainly to

Improve the surface finish

Increase productivity

Improve cutting efficiency

Reduce vibrations and chatter

Reducing vibrations and chatter is necessary in turning slender rods because these phenomena can negatively impact the surface finish, productivity, and cutting efficiency. Vibrations and chatter can cause the tool to vibrate and chatter against the workpiece, leading to poor surface finish, increased tool wear, and decreased cutting efficiency. By minimizing the transverse force, the likelihood of vibrations and chatter occurring is reduced, resulting in improved overall machining performance.

Explanation

Reducing vibrations and chatter is necessary in turning slender rods because these phenomena can negatively impact the surface finish, productivity, and cutting efficiency. Vibrations and chatter can cause the tool to vibrate and chatter against the workpiece, leading to poor surface finish, increased tool wear, and decreased cutting efficiency. By minimizing the transverse force, the likelihood of vibrations and chatter occurring is reduced, resulting in improved overall machining performance.

18. Wheel loading in grinding is defined as

Types of wheel bond fracture

Types of wheel grain fracture

Sticking of small particle on grinding wheel

None of the above

Wheel loading in grinding is defined as the phenomenon where small particles from the workpiece adhere to the surface of the grinding wheel during the grinding process. This can lead to a decrease in the cutting efficiency of the wheel, causing it to become less effective in removing material from the workpiece. Wheel loading can result in poor surface finish, increased heat generation, and reduced wheel life. Therefore, it is important to regularly clean and dress the grinding wheel to prevent wheel loading and maintain optimal grinding performance.

Explanation

Wheel loading in grinding is defined as the phenomenon where small particles from the workpiece adhere to the surface of the grinding wheel during the grinding process. This can lead to a decrease in the cutting efficiency of the wheel, causing it to become less effective in removing material from the workpiece. Wheel loading can result in poor surface finish, increased heat generation, and reduced wheel life. Therefore, it is important to regularly clean and dress the grinding wheel to prevent wheel loading and maintain optimal grinding performance.

19. Binding material used in cemented carbide tools is

Nickel

Cobalt

Chromium

Silicon

Cobalt is the correct answer because it is commonly used as a binding material in cemented carbide tools. Cemented carbide, also known as tungsten carbide, is a hard and durable material used in cutting tools, drills, and other applications. Cobalt acts as a binder in cemented carbide, holding the tungsten carbide particles together and providing strength and toughness to the tool. It helps improve the wear resistance and overall performance of the tool, making it suitable for various industrial applications.

Explanation

Cobalt is the correct answer because it is commonly used as a binding material in cemented carbide tools. Cemented carbide, also known as tungsten carbide, is a hard and durable material used in cutting tools, drills, and other applications. Cobalt acts as a binder in cemented carbide, holding the tungsten carbide particles together and providing strength and toughness to the tool. It helps improve the wear resistance and overall performance of the tool, making it suitable for various industrial applications.

20. According to kinectic theory of gases, at absolute zero

Specific heat of molecules reduced to zero

Kinectic energy of molecules reduced to zero

Volume of gas reduce to zero

Pressure of gas reduced to zero

According to the kinetic theory of gases, at absolute zero, the kinetic energy of molecules reduces to zero. This is because at absolute zero, the temperature is at its lowest possible value, causing the molecules to have minimal or no movement. Since kinetic energy is directly related to the movement of particles, when there is no movement, the kinetic energy is reduced to zero.

Explanation

According to the kinetic theory of gases, at absolute zero, the kinetic energy of molecules reduces to zero. This is because at absolute zero, the temperature is at its lowest possible value, causing the molecules to have minimal or no movement. Since kinetic energy is directly related to the movement of particles, when there is no movement, the kinetic energy is reduced to zero.

21. The fatigue life of a part Can be improved by

Electroplating

Polishing

Coating

Shot peening

Shot peening is a process in which small metal particles, called shot, are forcefully propelled onto the surface of a part. This creates compressive stresses on the surface, which helps to improve the fatigue life of the part. The shot peening process induces plastic deformation in the surface layer, which enhances the resistance of the part to fatigue crack initiation and propagation. This makes shot peening an effective method for improving the fatigue strength and durability of parts, ultimately increasing their overall fatigue life.

Explanation

Shot peening is a process in which small metal particles, called shot, are forcefully propelled onto the surface of a part. This creates compressive stresses on the surface, which helps to improve the fatigue life of the part. The shot peening process induces plastic deformation in the surface layer, which enhances the resistance of the part to fatigue crack initiation and propagation. This makes shot peening an effective method for improving the fatigue strength and durability of parts, ultimately increasing their overall fatigue life.

22. Centre of Pressure on an inclined plane is

At the centroid

Above the centroid

Below the centroid

At metacentre

The center of pressure on an inclined plane is below the centroid because the pressure distribution on the inclined plane is not uniform. The pressure is higher at the bottom of the plane and decreases as we move upwards. This results in a net force acting at a point below the centroid, causing the center of pressure to be below the centroid.

Explanation

The center of pressure on an inclined plane is below the centroid because the pressure distribution on the inclined plane is not uniform. The pressure is higher at the bottom of the plane and decreases as we move upwards. This results in a net force acting at a point below the centroid, causing the center of pressure to be below the centroid.

23. If the perimeter of a rectangle and a square each is equal to 80 cm and the difference of their areas is 100 sq cm. The sides of the rectangle are:

35 cm, 15 cm

30 cm, 10 cm

28 cm, 12 cm

25 cm, 15 cm

Let the length and width of the rectangle be L and W respectively. The perimeter of the rectangle is given by 2(L + W) = 80. Simplifying the equation gives L + W = 40. The area of the rectangle is given by L * W. The area of the square is given by S^2, where S is the side length of the square. The difference of their areas is 100, so L * W - S^2 = 100. Substituting L + W = 40 into the equation gives (40 - W) * W - S^2 = 100. By trial and error, we find that when W = 10 and S = 10, the equation is satisfied. Therefore, the sides of the rectangle are 30 cm and 10 cm.

Explanation

Let the length and width of the rectangle be L and W respectively. The perimeter of the rectangle is given by 2(L + W) = 80. Simplifying the equation gives L + W = 40. The area of the rectangle is given by L * W. The area of the square is given by S^2, where S is the side length of the square. The difference of their areas is 100, so L * W - S^2 = 100. Substituting L + W = 40 into the equation gives (40 - W) * W - S^2 = 100. By trial and error, we find that when W = 10 and S = 10, the equation is satisfied. Therefore, the sides of the rectangle are 30 cm and 10 cm.

24. The sum of the two numbers is 15 and their geometric mean is 20% lower than their arithmetric mean. Find the numbers

11, 4

12, 3

13, 2

10, 5

The sum of the two numbers is 15, which means that when we add the two numbers together, they equal 15. The geometric mean is 20% lower than the arithmetic mean, which means that the geometric mean is equal to 80% of the arithmetic mean. By setting up an equation, we can solve for the numbers. Let the two numbers be x and y. We have the following equations: x + y = 15 and (xy)^0.5 = 0.8((x + y)/2). Solving these equations, we find that x = 12 and y = 3.

Explanation

The sum of the two numbers is 15, which means that when we add the two numbers together, they equal 15. The geometric mean is 20% lower than the arithmetic mean, which means that the geometric mean is equal to 80% of the arithmetic mean. By setting up an equation, we can solve for the numbers. Let the two numbers be x and y. We have the following equations: x + y = 15 and (xy)^0.5 = 0.8((x + y)/2). Solving these equations, we find that x = 12 and y = 3.

25. Which one of the following is a cabinet minister of Agriculture Department

Radha Mohan Singh

Thavar singh Gehlot

Kalraj Mishra

M. Vainkaiya Naidu

Radha Mohan Singh is a cabinet minister of the Agriculture Department.

Explanation

Radha Mohan Singh is a cabinet minister of the Agriculture Department.

26. Presently Which one of the Following is a chief minister of Uttarakhand

Jitan Ram manjhi

Prakash singh Badal

Vijay Bahuguna

Harish Rawat

Harish Rawat is the correct answer because he is presently serving as the Chief Minister of Uttarakhand. The other options, Jitan Ram Manjhi, Prakash Singh Badal, and Vijay Bahuguna, are not relevant to Uttarakhand and are not currently holding the position of Chief Minister in that state.

Explanation

Harish Rawat is the correct answer because he is presently serving as the Chief Minister of Uttarakhand. The other options, Jitan Ram Manjhi, Prakash Singh Badal, and Vijay Bahuguna, are not relevant to Uttarakhand and are not currently holding the position of Chief Minister in that state.

27. Which of the following is hardest materials next to diamond

Aluminium oxide

Silicon carbide

Cubic boron nitride

Cemented carbide

Cubic boron nitride is the hardest material next to diamond. It has a similar crystal structure to diamond, which gives it exceptional hardness and resistance to wear. This material is often used in cutting tools and abrasives for grinding and machining applications where high levels of hardness and durability are required.

Explanation

Cubic boron nitride is the hardest material next to diamond. It has a similar crystal structure to diamond, which gives it exceptional hardness and resistance to wear. This material is often used in cutting tools and abrasives for grinding and machining applications where high levels of hardness and durability are required.

28. How many terms there in the Arithmetic Progression 20, 25, 30, ............130

22

23

21

24

In an arithmetic progression, each term is obtained by adding a constant difference to the previous term. In this case, the common difference is 5 (25 - 20 = 5), and the last term is 130. To find the number of terms, we can use the formula for the nth term of an arithmetic progression: an = a1 + (n-1)d, where an is the nth term, a1 is the first term, n is the number of terms, and d is the common difference. Plugging in the values, we get 130 = 20 + (n-1)5. Simplifying the equation, we have 110 = 5n - 5. Solving for n, we find that n = 23. Therefore, there are 23 terms in the arithmetic progression.

Explanation

In an arithmetic progression, each term is obtained by adding a constant difference to the previous term. In this case, the common difference is 5 (25 - 20 = 5), and the last term is 130. To find the number of terms, we can use the formula for the nth term of an arithmetic progression: an = a1 + (n-1)d, where an is the nth term, a1 is the first term, n is the number of terms, and d is the common difference. Plugging in the values, we get 130 = 20 + (n-1)5. Simplifying the equation, we have 110 = 5n - 5. Solving for n, we find that n = 23. Therefore, there are 23 terms in the arithmetic progression.

29. Ramesh can do a work in 10 days and Suresh can do the same work in 20 days. They work together for 5 days and then Ramesh goes away. In how many more days will Suresh finish the work

5 days

6.5 days

9 days

10 days

Ramesh can complete the work in 10 days, which means he can do 1/10th of the work in a day. Suresh can complete the work in 20 days, so he can do 1/20th of the work in a day. When they work together for 5 days, they complete a total of (1/10 + 1/20) * 5 = 3/10th of the work. This means that there is still 1 - 3/10 = 7/10th of the work remaining. Since Suresh is the only one working now, he will take 7/10 * 20 = 14 days to complete the remaining work. Therefore, Suresh will finish the work in 5 + 14 = 19 days.

Explanation

Ramesh can complete the work in 10 days, which means he can do 1/10th of the work in a day. Suresh can complete the work in 20 days, so he can do 1/20th of the work in a day. When they work together for 5 days, they complete a total of (1/10 + 1/20) * 5 = 3/10th of the work. This means that there is still 1 - 3/10 = 7/10th of the work remaining. Since Suresh is the only one working now, he will take 7/10 * 20 = 14 days to complete the remaining work. Therefore, Suresh will finish the work in 5 + 14 = 19 days.

30. A body floats in stable equilibrium

When its metacentre height is zero

When metacentre is sbove C.g.

When its c.g is below its centre of Buoyancy

None of the above

A body floats in stable equilibrium when its metacentre is above its center of gravity. This means that the point at which the buoyant force and the weight of the body intersect, known as the metacentre, is located above the center of gravity. This configuration ensures that any small disturbance or tilting of the body will cause a restoring moment that brings the body back to its original position. This is important for stability, as it prevents the body from easily tipping over or capsizing.

Explanation

A body floats in stable equilibrium when its metacentre is above its center of gravity. This means that the point at which the buoyant force and the weight of the body intersect, known as the metacentre, is located above the center of gravity. This configuration ensures that any small disturbance or tilting of the body will cause a restoring moment that brings the body back to its original position. This is important for stability, as it prevents the body from easily tipping over or capsizing.

31. In a unit cell of a body centered cubic space lattice the total number of atoms is

6

9

14

24

In a body-centered cubic (BCC) space lattice, each corner of the unit cell is shared by 8 neighboring unit cells, contributing 1/8th of an atom to the unit cell. Additionally, there is 1 atom located at the center of the unit cell. Therefore, the total number of atoms in a BCC unit cell is 1 + 1/8 = 9.

Explanation

In a body-centered cubic (BCC) space lattice, each corner of the unit cell is shared by 8 neighboring unit cells, contributing 1/8th of an atom to the unit cell. Additionally, there is 1 atom located at the center of the unit cell. Therefore, the total number of atoms in a BCC unit cell is 1 + 1/8 = 9.

32. A milling cutter having 8 teeth is rotating at 150 rpm. if the feed per tooth is 0.1 mm, the value of thew table speed in mm/min is

120

187

125

70

The table speed is calculated by multiplying the number of teeth on the milling cutter by the rotation speed and the feed per tooth. In this case, the milling cutter has 8 teeth, the rotation speed is 150 rpm, and the feed per tooth is 0.1 mm. Therefore, the table speed would be 8 x 150 x 0.1 = 120 mm/min.

Explanation

The table speed is calculated by multiplying the number of teeth on the milling cutter by the rotation speed and the feed per tooth. In this case, the milling cutter has 8 teeth, the rotation speed is 150 rpm, and the feed per tooth is 0.1 mm. Therefore, the table speed would be 8 x 150 x 0.1 = 120 mm/min.

33. In a solid circular bar subject to torsion, the shear stress is

Zero at extreme fibre and varies linearly to maxium value at axis

Zero at axis and varies linearly to maximum value at extreme fibre

Zero at extreme fibre and varies parabolically to the maximum value at axis

Zero at axis and varies parabolically to the maximum value at extreme fibre

In a solid circular bar subject to torsion, the shear stress is zero at the axis because there is no shear force acting on the axis. As we move away from the axis towards the extreme fiber, the shear stress increases linearly. This is because the shear force increases with the distance from the axis, resulting in a linear variation of shear stress. At the extreme fiber, the shear stress reaches its maximum value. Therefore, the correct answer is "Zero at axis and varies linearly to maximum value at extreme fiber."

Explanation

In a solid circular bar subject to torsion, the shear stress is zero at the axis because there is no shear force acting on the axis. As we move away from the axis towards the extreme fiber, the shear stress increases linearly. This is because the shear force increases with the distance from the axis, resulting in a linear variation of shear stress. At the extreme fiber, the shear stress reaches its maximum value. Therefore, the correct answer is "Zero at axis and varies linearly to maximum value at extreme fiber."

34. Consider the following statements regarding NC machine tools

They reduce non productive time

They reduce fixturing

Niether 1 nor 2

Both 1 and 2

NC machine tools are able to reduce non-productive time and fixturing. Non-productive time refers to the time spent on tasks that do not directly contribute to the production process, such as setting up the machine or changing tools. NC machine tools can automate these tasks, reducing the time wasted on non-productive activities. Additionally, these tools can also minimize fixturing requirements by using computer-controlled positioning and alignment, eliminating the need for extensive manual adjustments and setups. Therefore, both statements 1 and 2 are correct.

Explanation

NC machine tools are able to reduce non-productive time and fixturing. Non-productive time refers to the time spent on tasks that do not directly contribute to the production process, such as setting up the machine or changing tools. NC machine tools can automate these tasks, reducing the time wasted on non-productive activities. Additionally, these tools can also minimize fixturing requirements by using computer-controlled positioning and alignment, eliminating the need for extensive manual adjustments and setups. Therefore, both statements 1 and 2 are correct.

35. A Grinding wheel of 150mm diameter is rotating at 3000 rpm. The grinding speed is

7.5 π m/s

15π m/s

45π m/s

450π m/s

The grinding speed can be calculated using the formula: speed = (π * diameter * rpm) / 60. Substituting the given values, we get (π * 150 * 3000) / 60 = 7.5π m/s.

Explanation

The grinding speed can be calculated using the formula: speed = (π * diameter * rpm) / 60. Substituting the given values, we get (π * 150 * 3000) / 60 = 7.5π m/s.

36. The process of producing components in moulds without the application of pressure, is known as

Moulding

Laminating

Casting

Calendering

Casting is the correct answer because it refers to the process of producing components in moulds without the application of pressure. In casting, a liquid material, such as metal or plastic, is poured into a mould and allowed to solidify. This process is commonly used in manufacturing to create various products, such as metal parts, sculptures, and even dental restorations. Unlike moulding, laminating, and calendering, casting does not involve the application of pressure to shape the material.

Explanation

Casting is the correct answer because it refers to the process of producing components in moulds without the application of pressure. In casting, a liquid material, such as metal or plastic, is poured into a mould and allowed to solidify. This process is commonly used in manufacturing to create various products, such as metal parts, sculptures, and even dental restorations. Unlike moulding, laminating, and calendering, casting does not involve the application of pressure to shape the material.

37. IRNSS Stands For The

Indian Remote Navigation Satellte System

Indian Regional Navigation Satellite System

Internation Remote Navigation Satellite System

International Regional Navigation Satellite System

The correct answer is Indian Regional Navigation Satellite System. IRNSS is an acronym for Indian Regional Navigation Satellite System, which is a satellite-based navigation system developed by the Indian Space Research Organisation (ISRO). It is designed to provide accurate positioning and timing services in India and the surrounding regions.

Explanation

The correct answer is Indian Regional Navigation Satellite System. IRNSS is an acronym for Indian Regional Navigation Satellite System, which is a satellite-based navigation system developed by the Indian Space Research Organisation (ISRO). It is designed to provide accurate positioning and timing services in India and the surrounding regions.

38. The National institute for Oceanography is situated in

Panaji

Pune

Bangalore

Roorkee

The National Institute for Oceanography is situated in Panaji. Panaji is the capital city of the Indian state of Goa, which is known for its beautiful beaches and coastal areas. It is an ideal location for the National Institute for Oceanography as it provides easy access to the Arabian Sea and a diverse marine ecosystem for research and study purposes.

Explanation

The National Institute for Oceanography is situated in Panaji. Panaji is the capital city of the Indian state of Goa, which is known for its beautiful beaches and coastal areas. It is an ideal location for the National Institute for Oceanography as it provides easy access to the Arabian Sea and a diverse marine ecosystem for research and study purposes.

39. In a mixture of 80 litres of milk and water 25% of the mixture is milk. How much water should be added to the mixture so that milk becomes 20% of the mixture

20 litres

15 litres

25 litres

None of the above

To find the solution, we need to determine the amount of milk in the initial mixture. Since 25% of the mixture is milk, we can calculate that 80 * 0.25 = 20 litres of milk. To make milk 20% of the mixture, we need to add water. Let's assume we add 'x' litres of water. The total volume of the mixture will then be 80 + x litres. As per the question, milk should be 20% of the mixture, so 0.2 * (80 + x) = 20. Solving this equation, we find that x = 20 litres. Therefore, 20 litres of water should be added to the mixture.

Explanation

To find the solution, we need to determine the amount of milk in the initial mixture. Since 25% of the mixture is milk, we can calculate that 80 * 0.25 = 20 litres of milk. To make milk 20% of the mixture, we need to add water. Let's assume we add 'x' litres of water. The total volume of the mixture will then be 80 + x litres. As per the question, milk should be 20% of the mixture, so 0.2 * (80 + x) = 20. Solving this equation, we find that x = 20 litres. Therefore, 20 litres of water should be added to the mixture.

40. Cold shortness is defined as the

Fracture in room temperature below their recrystallization temperature

Brittelness in room temperature below their recrystallization temperature

Loss of ductility above recrystallization temperature

Decrease of brittleness in room temperature

Cold shortness refers to the brittleness of a material at room temperature when it is below its recrystallization temperature. This means that the material becomes more prone to fracturing or breaking when exposed to stress or impact at lower temperatures. The loss of ductility and decrease in brittleness occur above the recrystallization temperature, not below it. Therefore, the correct answer is brittleness in room temperature below their recrystallization temperature.

Explanation

Cold shortness refers to the brittleness of a material at room temperature when it is below its recrystallization temperature. This means that the material becomes more prone to fracturing or breaking when exposed to stress or impact at lower temperatures. The loss of ductility and decrease in brittleness occur above the recrystallization temperature, not below it. Therefore, the correct answer is brittleness in room temperature below their recrystallization temperature.

41. In powder metallurgy, the operation carried out to improve the bearing property of a bush is called

Infilteration

Impregnation

Plating

Sintering

Impregnation is the operation carried out in powder metallurgy to improve the bearing property of a bush. This process involves filling the porous structure of the bush with a lubricant or a solid material to enhance its performance and reduce friction. Impregnation helps to increase the load-carrying capacity and wear resistance of the bush, making it suitable for bearing applications.

Explanation

Impregnation is the operation carried out in powder metallurgy to improve the bearing property of a bush. This process involves filling the porous structure of the bush with a lubricant or a solid material to enhance its performance and reduce friction. Impregnation helps to increase the load-carrying capacity and wear resistance of the bush, making it suitable for bearing applications.

42. The pressure in pascals at a depth of 1 m below the free surface of a body of water will be equal to

1 Pa

98.1 Pa

981 Pa

9810 Pa

The pressure in a body of water increases with depth due to the weight of the water above it. This is known as hydrostatic pressure. The pressure at a depth of 1 m below the free surface of the water will be equal to the weight of the water column above it, which is 9810 Pa.

Explanation

The pressure in a body of water increases with depth due to the weight of the water above it. This is known as hydrostatic pressure. The pressure at a depth of 1 m below the free surface of the water will be equal to the weight of the water column above it, which is 9810 Pa.

43. A Lead Screw with half nuts in a lathe, Free to Rotate in both Direction has

V-threads

Whithworth threads

Buttress threads

ACME threads

ACME threads are the correct answer because they are commonly used in lead screws with half nuts in lathes. ACME threads have a trapezoidal shape with a 29-degree thread angle, which allows for smooth and efficient movement in both directions. They are designed to withstand heavy loads and provide high accuracy and repeatability. ACME threads are widely used in applications where precise linear motion is required, such as in CNC machines and industrial equipment.

Explanation

ACME threads are the correct answer because they are commonly used in lead screws with half nuts in lathes. ACME threads have a trapezoidal shape with a 29-degree thread angle, which allows for smooth and efficient movement in both directions. They are designed to withstand heavy loads and provide high accuracy and repeatability. ACME threads are widely used in applications where precise linear motion is required, such as in CNC machines and industrial equipment.

44. Among the conventional, machining process maximium specifiec energy is consumed in

Grinding

Drilling

Planing

Turnig

Grinding consumes the maximum specific energy among the conventional machining processes. This is because grinding involves the use of abrasive particles to remove material from a workpiece, which requires a significant amount of energy. The abrasive particles continuously remove small chips from the workpiece surface, resulting in high friction and heat generation. This high energy consumption is necessary to achieve the desired surface finish and dimensional accuracy in grinding operations.

Explanation

Grinding consumes the maximum specific energy among the conventional machining processes. This is because grinding involves the use of abrasive particles to remove material from a workpiece, which requires a significant amount of energy. The abrasive particles continuously remove small chips from the workpiece surface, resulting in high friction and heat generation. This high energy consumption is necessary to achieve the desired surface finish and dimensional accuracy in grinding operations.

45. When the column is fixed at both ends, corresponding Euler critical load is

π2 E I/L2

2π2 E I/L2

3π2 E I/L2

4π2 E I/L2

When a column is fixed at both ends, the corresponding Euler critical load can be calculated using the formula 4π^2 E I/L^2. This formula takes into account the modulus of elasticity (E), the moment of inertia (I), and the length of the column (L). The critical load represents the maximum load that the column can sustain without buckling, and it is directly proportional to the square of the length and inversely proportional to the modulus of elasticity and the moment of inertia. Therefore, the correct answer is 4π^2 E I/L^2.

Explanation

When a column is fixed at both ends, the corresponding Euler critical load can be calculated using the formula 4π^2 E I/L^2. This formula takes into account the modulus of elasticity (E), the moment of inertia (I), and the length of the column (L). The critical load represents the maximum load that the column can sustain without buckling, and it is directly proportional to the square of the length and inversely proportional to the modulus of elasticity and the moment of inertia. Therefore, the correct answer is 4π^2 E I/L^2.

46. The correct sequence of the given materials in descending order of their weldability is

Mild steel, Copper, Cast Iron, Al

Cast iron, Al, Mild steel, Copper

Copper, Cast iron, Mild steel, Al

Al, Cast iron, Copper, Mild steel

The correct sequence of materials in descending order of their weldability is mild steel, copper, cast iron, and aluminum. This means that mild steel has the highest weldability, followed by copper, cast iron, and aluminum. Weldability refers to how easily a material can be welded or joined together using various welding techniques. In this case, mild steel is the most weldable material, while aluminum is the least weldable.

Explanation

The correct sequence of materials in descending order of their weldability is mild steel, copper, cast iron, and aluminum. This means that mild steel has the highest weldability, followed by copper, cast iron, and aluminum. Weldability refers to how easily a material can be welded or joined together using various welding techniques. In this case, mild steel is the most weldable material, while aluminum is the least weldable.

47. Which one of the following instrument used in Light Detector Test

Polygraph

Udometer

Cardiogram

Odometer

A polygraph is an instrument used in a Light Detector Test. A polygraph, also known as a lie detector, measures and records several physiological indicators such as blood pressure, pulse, respiration, and skin conductivity while a person is being questioned. It is commonly used in investigations or interrogations to determine if someone is being truthful or deceptive.

Explanation

A polygraph is an instrument used in a Light Detector Test. A polygraph, also known as a lie detector, measures and records several physiological indicators such as blood pressure, pulse, respiration, and skin conductivity while a person is being questioned. It is commonly used in investigations or interrogations to determine if someone is being truthful or deceptive.

48. Bearing alloy preferred for light loads bearing is

Phospher bronze

White metal

Monel metal

Bronze

White metal is preferred for light loads bearing because it has excellent anti-friction properties and can withstand low pressure and speeds. It is a soft and ductile alloy made primarily of tin, lead, and antimony. The low melting point of white metal allows it to conform to the shape of the bearing surface, reducing friction and wear. Additionally, white metal has good lubricating properties and can withstand high temperatures without losing its load-carrying capacity.

Explanation

White metal is preferred for light loads bearing because it has excellent anti-friction properties and can withstand low pressure and speeds. It is a soft and ductile alloy made primarily of tin, lead, and antimony. The low melting point of white metal allows it to conform to the shape of the bearing surface, reducing friction and wear. Additionally, white metal has good lubricating properties and can withstand high temperatures without losing its load-carrying capacity.

49. In a mechanical shaper the length of stroke is increased by

Increasing the centre distance of bull gear and crank pin

Decreasing the centre distance of bull gear and crank pin

Increasing the length of arm

Decreasing the length of slot in the slotted lever

Increasing the center distance of the bull gear and crank pin in a mechanical shaper will increase the length of stroke. This is because the center distance determines the distance between the axis of rotation of the bull gear and the axis of rotation of the crank pin. By increasing this distance, the crank pin will have a larger circular path, resulting in a longer stroke of the shaper.

Explanation

Increasing the center distance of the bull gear and crank pin in a mechanical shaper will increase the length of stroke. This is because the center distance determines the distance between the axis of rotation of the bull gear and the axis of rotation of the crank pin. By increasing this distance, the crank pin will have a larger circular path, resulting in a longer stroke of the shaper.

50. The straigh grades of cemented carbide cutting tool materials contain

Tunsten Carbide only

Tungsten carbide and titanium carbide

Tungsten carbide and cobalt

Tungsten carbide and cobalt carbide

The correct answer is tungsten carbide and cobalt. Cemented carbide cutting tool materials are made by combining tungsten carbide, which provides hardness and wear resistance, with cobalt, which acts as a binder to hold the tungsten carbide particles together. This combination of tungsten carbide and cobalt results in a strong and durable cutting tool material that is commonly used in machining applications.

Explanation

The correct answer is tungsten carbide and cobalt. Cemented carbide cutting tool materials are made by combining tungsten carbide, which provides hardness and wear resistance, with cobalt, which acts as a binder to hold the tungsten carbide particles together. This combination of tungsten carbide and cobalt results in a strong and durable cutting tool material that is commonly used in machining applications.

51. With increase in pressure the bulk modulus of elasticity

Increases

Decreases

Remains constant

Increase upto certain limit and then decrease

The bulk modulus of elasticity is a measure of a material's resistance to compression when subjected to an external force or pressure. When the pressure on a material increases, the material becomes more resistant to compression, causing an increase in the bulk modulus of elasticity. This means that the material becomes stiffer and less compressible under higher pressure. Therefore, the correct answer is that the bulk modulus of elasticity increases with an increase in pressure.

Explanation

The bulk modulus of elasticity is a measure of a material's resistance to compression when subjected to an external force or pressure. When the pressure on a material increases, the material becomes more resistant to compression, causing an increase in the bulk modulus of elasticity. This means that the material becomes stiffer and less compressible under higher pressure. Therefore, the correct answer is that the bulk modulus of elasticity increases with an increase in pressure.

52. Which one of thermodynamic Properties is not dependent upon the mass of substance

Kinectic Energy

Volume

Density

Entropy

Density is a thermodynamic property that is not dependent upon the mass of a substance. Density is defined as the mass per unit volume of a substance. It is an intensive property, meaning it does not change with the amount of substance present. Therefore, even if the mass of a substance changes, its density remains the same as long as the volume remains constant. This makes density independent of the mass of the substance.

Explanation

Density is a thermodynamic property that is not dependent upon the mass of a substance. Density is defined as the mass per unit volume of a substance. It is an intensive property, meaning it does not change with the amount of substance present. Therefore, even if the mass of a substance changes, its density remains the same as long as the volume remains constant. This makes density independent of the mass of the substance.

53. In the griding wheel have specification A60G7B23, B stands for the

Resinoid bond

Rubber bond

Shellac bond

Silicate bond

The correct answer is resinoid bond. In the given specification A60G7B23, the letter "B" represents the resinoid bond. Resinoid bond refers to a type of bond used in grinding wheels where a resin-based material is used to hold the abrasive grains together. This bond type offers good performance and durability, making it suitable for various grinding applications.

Explanation

The correct answer is resinoid bond. In the given specification A60G7B23, the letter "B" represents the resinoid bond. Resinoid bond refers to a type of bond used in grinding wheels where a resin-based material is used to hold the abrasive grains together. This bond type offers good performance and durability, making it suitable for various grinding applications.

54. The flux coating of an electric arc electrode has a melting point

Higher than metallic core

Lower than metallic core

The same as the metallic core

The same as the metal being welded

The flux coating of an electric arc electrode has a melting point that is higher than the metallic core. This is because the flux coating is designed to provide a protective barrier during the welding process. It melts at a higher temperature than the metallic core to ensure that it remains intact and effectively shields the weld from contaminants and oxidation.

Explanation

The flux coating of an electric arc electrode has a melting point that is higher than the metallic core. This is because the flux coating is designed to provide a protective barrier during the welding process. It melts at a higher temperature than the metallic core to ensure that it remains intact and effectively shields the weld from contaminants and oxidation.

55. If metallic wire is Streched doubled then speciefic resistance of wire will

Doubled

Halved

Remain same

Increase by four times

When a metallic wire is stretched, its length increases while its cross-sectional area decreases. The specific resistance of a material is defined as the resistance of a wire of unit length and unit cross-sectional area. Since both the length and cross-sectional area change in the same proportion, the specific resistance remains constant. Therefore, when a metallic wire is stretched, its specific resistance will remain the same.

Explanation

When a metallic wire is stretched, its length increases while its cross-sectional area decreases. The specific resistance of a material is defined as the resistance of a wire of unit length and unit cross-sectional area. Since both the length and cross-sectional area change in the same proportion, the specific resistance remains constant. Therefore, when a metallic wire is stretched, its specific resistance will remain the same.

56. Line imperfection in a crystal is called

Schottky defect

Frenkel defect

Edge dislocation

Miller defect

An edge dislocation refers to a line imperfection in a crystal structure where the arrangement of atoms is disrupted along a line, creating a boundary between regions of different crystal orientations. This type of defect occurs when an extra half-plane of atoms is inserted or removed from the crystal lattice structure. It causes localized strain and distortion in the crystal, affecting its mechanical properties. Therefore, edge dislocation is the correct answer for the given question.

Explanation

An edge dislocation refers to a line imperfection in a crystal structure where the arrangement of atoms is disrupted along a line, creating a boundary between regions of different crystal orientations. This type of defect occurs when an extra half-plane of atoms is inserted or removed from the crystal lattice structure. It causes localized strain and distortion in the crystal, affecting its mechanical properties. Therefore, edge dislocation is the correct answer for the given question.

57. Modulus of section of hollow tube of outer diameter 2d and innner diameter is

3πd3/64

7πd3/64

15πd3/64

3πd3/8

The correct answer is 15πd3/64. The modulus of section of a hollow tube is a measure of its resistance to deformation. It is calculated by dividing the moment of inertia of the section by the distance from the neutral axis. In this case, the moment of inertia is given by (π/64)(D^4 - d^4), where D is the outer diameter and d is the inner diameter. Substituting the given values, we get (π/64)((2d)^4 - d^4) = (15πd^3)/64.

Explanation

The correct answer is 15πd3/64. The modulus of section of a hollow tube is a measure of its resistance to deformation. It is calculated by dividing the moment of inertia of the section by the distance from the neutral axis. In this case, the moment of inertia is given by (π/64)(D^4 - d^4), where D is the outer diameter and d is the inner diameter. Substituting the given values, we get (π/64)((2d)^4 - d^4) = (15πd^3)/64.

58. The open Circuit Voltage OCV in arc welding ranges from

40 to 80 V

100 to 150 V

200 to 220 V

400 to 440 V

The open circuit voltage (OCV) in arc welding typically ranges from 40 to 80 V. This voltage range is necessary to establish and maintain the arc between the welding electrode and the workpiece. It provides the necessary energy to ionize the air gap and create a conductive path for the electric current. Higher OCV values may be used for specific welding processes or materials, but the 40 to 80 V range is commonly used for general arc welding applications.

Explanation

The open circuit voltage (OCV) in arc welding typically ranges from 40 to 80 V. This voltage range is necessary to establish and maintain the arc between the welding electrode and the workpiece. It provides the necessary energy to ionize the air gap and create a conductive path for the electric current. Higher OCV values may be used for specific welding processes or materials, but the 40 to 80 V range is commonly used for general arc welding applications.

59. Find the area of an isosceles right-angled triangle whose hypotenuse is 8 cm

32 sq m

24 sq m

16 sq m

None of the above

The area of a triangle is given by the formula A = 1/2 * base * height. In an isosceles right-angled triangle, the base and height are equal. Since the hypotenuse is given as 8 cm, we can use the Pythagorean theorem to find the length of the base and height. The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. In this case, the base and height are equal, so we can call them x. Using the theorem, we have x^2 + x^2 = 8^2. Simplifying this equation, we get 2x^2 = 64. Dividing both sides by 2, we get x^2 = 32. Taking the square root of both sides, we get x = √32. Therefore, the base and height of the triangle are both √32 cm. Finally, we can calculate the area of the triangle using the formula A = 1/2 * base * height, which gives us A = 1/2 * √32 * √32 = 1/2 * 32 = 16 sq cm. Therefore, the correct answer is 16 sq m.

Explanation

The area of a triangle is given by the formula A = 1/2 * base * height. In an isosceles right-angled triangle, the base and height are equal. Since the hypotenuse is given as 8 cm, we can use the Pythagorean theorem to find the length of the base and height. The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. In this case, the base and height are equal, so we can call them x. Using the theorem, we have x^2 + x^2 = 8^2. Simplifying this equation, we get 2x^2 = 64. Dividing both sides by 2, we get x^2 = 32. Taking the square root of both sides, we get x = √32. Therefore, the base and height of the triangle are both √32 cm. Finally, we can calculate the area of the triangle using the formula A = 1/2 * base * height, which gives us A = 1/2 * √32 * √32 = 1/2 * 32 = 16 sq cm. Therefore, the correct answer is 16 sq m.

60. Ratio between inertial forces and the square root of pressure forces is known as

Euler number

Weber number

Froude number

Mach number

The Euler number is a dimensionless number that represents the ratio between inertial forces and the square root of pressure forces. It is commonly used in fluid dynamics to analyze the flow of fluids, particularly in situations where both inertial and pressure forces are significant. The Euler number helps determine the dominant forces at play and is used to classify different flow regimes.

Explanation

The Euler number is a dimensionless number that represents the ratio between inertial forces and the square root of pressure forces. It is commonly used in fluid dynamics to analyze the flow of fluids, particularly in situations where both inertial and pressure forces are significant. The Euler number helps determine the dominant forces at play and is used to classify different flow regimes.

61. A bicycle makes 5000 revolutions in moving 11 km. What is the radius of the wheel

70 cm

135 cm

17.5 cm

35 cm

In order to find the radius of the wheel, we need to use the formula: Distance = 2πr, where r is the radius of the wheel. We are given that the bicycle makes 5000 revolutions in moving 11 km. Since each revolution covers the circumference of the wheel, we can calculate the total distance covered by the bicycle as 5000 times the circumference of the wheel. Dividing this distance by 11 km, we can find the circumference of the wheel. Finally, by dividing the circumference by 2π, we can calculate the radius of the wheel. The correct answer is 35 cm.

Explanation

In order to find the radius of the wheel, we need to use the formula: Distance = 2πr, where r is the radius of the wheel. We are given that the bicycle makes 5000 revolutions in moving 11 km. Since each revolution covers the circumference of the wheel, we can calculate the total distance covered by the bicycle as 5000 times the circumference of the wheel. Dividing this distance by 11 km, we can find the circumference of the wheel. Finally, by dividing the circumference by 2π, we can calculate the radius of the wheel. The correct answer is 35 cm.

62. What is the mean by 0.2 % proof stress means

Stress corresponding to 0.2% strain

0.2 % of ultimate stress

0.2% of yield stress

The stress at which if unloading is made there will be 0.2 % permanent set

The correct answer is "the stress at which if unloading is made there will be 0.2% permanent set." This means that when a material is loaded to a certain stress level and then unloaded, there will be a permanent deformation or set of 0.2% of the original length. This indicates the point at which the material starts to exhibit plastic deformation and is commonly used to measure the strength and ductility of materials.

Explanation

The correct answer is "the stress at which if unloading is made there will be 0.2% permanent set." This means that when a material is loaded to a certain stress level and then unloaded, there will be a permanent deformation or set of 0.2% of the original length. This indicates the point at which the material starts to exhibit plastic deformation and is commonly used to measure the strength and ductility of materials.

63. A body of mass 10 kg moving with the velocity of 1 m/s is acted upon by a force of 50 N for two Seconds. The final velocity will be

22 m/s

10 m/s

21 m/s

11 m/s

When a force is applied to an object, it causes a change in its velocity. This change in velocity is determined by Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the force applied is 50 N and the mass of the object is 10 kg. Therefore, the acceleration can be calculated as 50 N / 10 kg = 5 m/s². Since the object is initially moving with a velocity of 1 m/s and the force is applied for 2 seconds, the change in velocity can be calculated as acceleration multiplied by time, which is 5 m/s² * 2 s = 10 m/s. Therefore, the final velocity will be the initial velocity (1 m/s) plus the change in velocity (10 m/s), which is 1 m/s + 10 m/s = 11 m/s.

Explanation

When a force is applied to an object, it causes a change in its velocity. This change in velocity is determined by Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the force applied is 50 N and the mass of the object is 10 kg. Therefore, the acceleration can be calculated as 50 N / 10 kg = 5 m/s². Since the object is initially moving with a velocity of 1 m/s and the force is applied for 2 seconds, the change in velocity can be calculated as acceleration multiplied by time, which is 5 m/s² * 2 s = 10 m/s. Therefore, the final velocity will be the initial velocity (1 m/s) plus the change in velocity (10 m/s), which is 1 m/s + 10 m/s = 11 m/s.

64. The average of 5 members is 21 years. If the age of the youngest member be 5 years. Find the average age of the family at the birth of the youngest member.

24 years

25 years

20 years

28 years

If the average age of 5 members is 21 years and the age of the youngest member is 5 years, then the sum of the ages of the other 4 members must be 4 * 21 = 84 years. Since the average age at the birth of the youngest member is the average age of the family without the youngest member, we can calculate it by subtracting the age of the youngest member from the sum of the ages of the other 4 members. Therefore, the average age at the birth of the youngest member is (84 - 5) / 4 = 20 years.

Explanation

If the average age of 5 members is 21 years and the age of the youngest member is 5 years, then the sum of the ages of the other 4 members must be 4 * 21 = 84 years. Since the average age at the birth of the youngest member is the average age of the family without the youngest member, we can calculate it by subtracting the age of the youngest member from the sum of the ages of the other 4 members. Therefore, the average age at the birth of the youngest member is (84 - 5) / 4 = 20 years.

65. The bottles from thermo plastic materials are made by

Compression moulding

Extrusion with mandrel

Injection moulding

Blow moulding

Blow molding is the correct answer because it is the process used to manufacture bottles from thermo plastic materials. In blow molding, a hollow tube of plastic called a parison is formed using either extrusion or injection molding. The parison is then placed in a mold, and air is blown into it, causing the plastic to expand and take the shape of the mold. This process is commonly used for producing bottles and other hollow plastic objects.

Explanation

Blow molding is the correct answer because it is the process used to manufacture bottles from thermo plastic materials. In blow molding, a hollow tube of plastic called a parison is formed using either extrusion or injection molding. The parison is then placed in a mold, and air is blown into it, causing the plastic to expand and take the shape of the mold. This process is commonly used for producing bottles and other hollow plastic objects.

66. If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be

Higher than surface of liquid

Same as the surface of liquid

Lower than the surface of liquid

Unpredictable

When the cohesion between molecules of a fluid is greater than the adhesion between the fluid and glass, the fluid tends to stick to itself more than it sticks to the glass. As a result, the fluid will be pulled down and form a concave meniscus in the dipped glass tube. This means that the free level of the fluid will be lower than the surface of the liquid.

Explanation

When the cohesion between molecules of a fluid is greater than the adhesion between the fluid and glass, the fluid tends to stick to itself more than it sticks to the glass. As a result, the fluid will be pulled down and form a concave meniscus in the dipped glass tube. This means that the free level of the fluid will be lower than the surface of the liquid.

67. Which of the following materials used for car tyres as a standard material

Styrene butadiene rubber

Butyl rubber

Nitrile rubber

Any one of the above

Styrene butadiene rubber (SBR) is commonly used as a standard material for car tires. It is a synthetic rubber that offers a good balance of durability, traction, and fuel efficiency. SBR is known for its excellent abrasion resistance and high tensile strength, making it suitable for withstanding the demands of everyday driving. Additionally, SBR provides good grip on both wet and dry surfaces, ensuring safety on the road. Due to these properties, SBR is widely used in the automotive industry as a standard material for car tires.

Explanation

Styrene butadiene rubber (SBR) is commonly used as a standard material for car tires. It is a synthetic rubber that offers a good balance of durability, traction, and fuel efficiency. SBR is known for its excellent abrasion resistance and high tensile strength, making it suitable for withstanding the demands of everyday driving. Additionally, SBR provides good grip on both wet and dry surfaces, ensuring safety on the road. Due to these properties, SBR is widely used in the automotive industry as a standard material for car tires.

68. The famous super computer PARAM-10000 is developed by

DRDO

C-DAC, Pune

C-Dot, Banglore

IIT-Bombay

The famous supercomputer PARAM-10000 was developed by C-DAC, Pune. C-DAC, also known as the Centre for Development of Advanced Computing, is a research and development organization under the Ministry of Electronics and Information Technology, Government of India. They are known for their expertise in high-performance computing and have developed several supercomputers in India.

Explanation

The famous supercomputer PARAM-10000 was developed by C-DAC, Pune. C-DAC, also known as the Centre for Development of Advanced Computing, is a research and development organization under the Ministry of Electronics and Information Technology, Government of India. They are known for their expertise in high-performance computing and have developed several supercomputers in India.

69. Which of the following is gear finishing operation

Hobbing

Shaping

Milling

Saving or burnishing

Saving or burnishing is a gear finishing operation that involves the use of a burnishing tool to smooth the surface of the gear and improve its finish. This process helps to reduce friction and wear, as well as improve the overall performance and longevity of the gear. Hobbing, shaping, and milling are all gear cutting operations, not finishing operations.

Explanation

Saving or burnishing is a gear finishing operation that involves the use of a burnishing tool to smooth the surface of the gear and improve its finish. This process helps to reduce friction and wear, as well as improve the overall performance and longevity of the gear. Hobbing, shaping, and milling are all gear cutting operations, not finishing operations.

70. Trepanning is performed for

Finishing a drilled hole

Producing a Large hole without drilling

Truing a hole for Alignment

Enlarging a Drilled hole

Trepanning is a machining process used to produce large holes in a workpiece without the need for drilling. It involves removing a solid disk-shaped piece of material from the center of the workpiece, leaving behind a large hole. This method is particularly useful when drilling a large hole using conventional drilling techniques is not feasible or practical. Trepanning can be performed using various tools and techniques, such as trepanning drills or trepanning heads, and is commonly used in industries such as aerospace, oil and gas, and automotive for applications that require large holes.

Explanation

Trepanning is a machining process used to produce large holes in a workpiece without the need for drilling. It involves removing a solid disk-shaped piece of material from the center of the workpiece, leaving behind a large hole. This method is particularly useful when drilling a large hole using conventional drilling techniques is not feasible or practical. Trepanning can be performed using various tools and techniques, such as trepanning drills or trepanning heads, and is commonly used in industries such as aerospace, oil and gas, and automotive for applications that require large holes.

71. Brasses and Bronze is welded by

Neutral Flame OAW

Reducing Flame OAW

Oxidising Flame OAW

MIG Welding

The correct answer is Oxidising Flame OAW. Oxidising Flame OAW (Oxy-Acetylene Welding) is suitable for welding brasses and bronze because it provides the right amount of oxygen to promote oxidation and remove impurities from the metal surface. This helps in achieving a clean and strong weld joint. The oxidizing flame has a slightly excess of oxygen compared to the fuel gas, which creates a hotter flame and ensures proper fusion of the base metals.

Explanation

The correct answer is Oxidising Flame OAW. Oxidising Flame OAW (Oxy-Acetylene Welding) is suitable for welding brasses and bronze because it provides the right amount of oxygen to promote oxidation and remove impurities from the metal surface. This helps in achieving a clean and strong weld joint. The oxidizing flame has a slightly excess of oxygen compared to the fuel gas, which creates a hotter flame and ensures proper fusion of the base metals.

72. Antivius is a

System software

Application software

Utilities software

None of the above

Antivirus software is categorized as utilities software because it is designed to perform specific tasks that help maintain and optimize the computer system. Antivirus software is primarily used to detect, prevent, and remove malicious software (such as viruses, worms, and Trojans) from a computer. It helps in protecting the system from potential threats and ensuring its smooth functioning. Therefore, the correct answer is utilities software.

Explanation

Antivirus software is categorized as utilities software because it is designed to perform specific tasks that help maintain and optimize the computer system. Antivirus software is primarily used to detect, prevent, and remove malicious software (such as viruses, worms, and Trojans) from a computer. It helps in protecting the system from potential threats and ensuring its smooth functioning. Therefore, the correct answer is utilities software.

73. In FIFA 2014 Woldcup the Golden boot award winner " James Rodrigreze" is player of which country

Germany

Brazil

Argentina

Columbia

James Rodriguez, the winner of the Golden Boot award in the 2014 FIFA World Cup, is from Colombia.

Explanation

James Rodriguez, the winner of the Golden Boot award in the 2014 FIFA World Cup, is from Colombia.

74. Refractive index for light is defined as the

Ratio of speed of light in vaccum to speed of light in the medium

Ratio of speed of light in medium to speed of light in vaccum

Ratio of speed of light in denser medium to rarer medium

Ratio of speed of light rarer medium to that of denser medium

The refractive index for light is defined as the ratio of the speed of light in vacuum to the speed of light in the medium. This means that it measures how much the speed of light changes when it passes from vacuum to a particular medium. The higher the refractive index, the slower the speed of light in that medium compared to vacuum.

Explanation

The refractive index for light is defined as the ratio of the speed of light in vacuum to the speed of light in the medium. This means that it measures how much the speed of light changes when it passes from vacuum to a particular medium. The higher the refractive index, the slower the speed of light in that medium compared to vacuum.

75. The flow of water in a pipe of diameter 3000 mm can be measured by

Venturimeter

Rotameter

Pitot tube

Orifice meter

A pitot tube can be used to measure the flow of water in a pipe of diameter 3000 mm. A pitot tube is a device that measures the velocity of a fluid by measuring the difference in pressure between the fluid flow and a static reference point. It consists of a tube with one end facing the fluid flow and the other end connected to a pressure gauge. As the fluid flows into the pitot tube, it creates a pressure difference, which can be used to determine the velocity of the fluid and hence the flow rate.

Explanation

A pitot tube can be used to measure the flow of water in a pipe of diameter 3000 mm. A pitot tube is a device that measures the velocity of a fluid by measuring the difference in pressure between the fluid flow and a static reference point. It consists of a tube with one end facing the fluid flow and the other end connected to a pressure gauge. As the fluid flows into the pitot tube, it creates a pressure difference, which can be used to determine the velocity of the fluid and hence the flow rate.

76. The most suitable type of bearing for carrying very heavy loads with slow speed is

Hydrodynamic Bearing

Ball bearing

Roller bearing

Hydrostatic bearing

A hydrostatic bearing is the most suitable type of bearing for carrying very heavy loads with slow speed. This type of bearing uses a fluid film to separate the surfaces of the bearing, allowing for smooth and efficient movement even under heavy loads. The fluid film provides a cushioning effect, reducing friction and wear on the bearing surfaces. This makes hydrostatic bearings ideal for applications where heavy loads need to be carried at slow speeds, as they can handle the weight and provide the necessary support and stability.

Explanation

A hydrostatic bearing is the most suitable type of bearing for carrying very heavy loads with slow speed. This type of bearing uses a fluid film to separate the surfaces of the bearing, allowing for smooth and efficient movement even under heavy loads. The fluid film provides a cushioning effect, reducing friction and wear on the bearing surfaces. This makes hydrostatic bearings ideal for applications where heavy loads need to be carried at slow speeds, as they can handle the weight and provide the necessary support and stability.

77. In drawing operation metal flows due to

Ductility

Work hardening

Plasticity

Shearing

In a drawing operation, metal flows due to plasticity. Plasticity refers to the ability of a material to undergo permanent deformation without fracture. When a metal is subjected to a drawing operation, it is stretched and reshaped without breaking, thanks to its plasticity. This property allows the metal to be easily formed into desired shapes and sizes.

Explanation

In a drawing operation, metal flows due to plasticity. Plasticity refers to the ability of a material to undergo permanent deformation without fracture. When a metal is subjected to a drawing operation, it is stretched and reshaped without breaking, thanks to its plasticity. This property allows the metal to be easily formed into desired shapes and sizes.

78. In Centreless Grinding, The workpiece Centre will be

Above the line joining the two wheel centres

Below the line joining the centres

On the line joining the wheel centres

At the intersection of the of the line joining the wheel centres with the work plate plane

In centreless grinding, the workpiece is positioned above the line joining the two wheel centres. This is because centreless grinding is a machining process where the workpiece is supported by a work plate and does not require a center or chuck to hold it in place. The two grinding wheels rotate in opposite directions and the workpiece is fed between them. The workpiece is positioned above the line joining the wheel centres to ensure that it is properly supported and guided during the grinding process.

Explanation

In centreless grinding, the workpiece is positioned above the line joining the two wheel centres. This is because centreless grinding is a machining process where the workpiece is supported by a work plate and does not require a center or chuck to hold it in place. The two grinding wheels rotate in opposite directions and the workpiece is fed between them. The workpiece is positioned above the line joining the wheel centres to ensure that it is properly supported and guided during the grinding process.

79. To raising the yield point of low carbon steel which one of the following added

Silicon carbide

Carbon

Phosphorus

Sulpher

Phosphorus is added to low carbon steel in order to raise its yield point. Phosphorus acts as a solid solution strengthener, increasing the strength and hardness of the steel. It also improves the machinability and formability of the steel. Silicon carbide is not typically added to low carbon steel for this purpose. Carbon is already present in low carbon steel and does not need to be added separately. Sulphur is sometimes added to improve machinability, but it does not significantly affect the yield point of the steel.

Explanation

Phosphorus is added to low carbon steel in order to raise its yield point. Phosphorus acts as a solid solution strengthener, increasing the strength and hardness of the steel. It also improves the machinability and formability of the steel. Silicon carbide is not typically added to low carbon steel for this purpose. Carbon is already present in low carbon steel and does not need to be added separately. Sulphur is sometimes added to improve machinability, but it does not significantly affect the yield point of the steel.

80. Helix angle of a fast helix drill is normally

35

60

90

5

The helix angle of a fast helix drill is normally 35 degrees. The helix angle refers to the angle formed between the cutting edge of the drill bit and a plane perpendicular to the axis of the drill. A smaller helix angle allows for more aggressive cutting action, making it suitable for drilling softer materials. A helix angle of 35 degrees strikes a balance between cutting efficiency and chip evacuation, making it a common choice for fast helix drills.

Explanation

The helix angle of a fast helix drill is normally 35 degrees. The helix angle refers to the angle formed between the cutting edge of the drill bit and a plane perpendicular to the axis of the drill. A smaller helix angle allows for more aggressive cutting action, making it suitable for drilling softer materials. A helix angle of 35 degrees strikes a balance between cutting efficiency and chip evacuation, making it a common choice for fast helix drills.

81. During Phase change of Pure substance which of the following is not altered

Entropy

Volume

Density

Pressure

During the phase change of a pure substance, the pressure remains constant. This is because phase change occurs at a specific temperature and pressure known as the boiling point or melting point. At this point, the substance undergoes a change in its physical state (solid to liquid or liquid to gas) while the pressure remains constant. Therefore, pressure is not altered during the phase change of a pure substance.

Explanation

During the phase change of a pure substance, the pressure remains constant. This is because phase change occurs at a specific temperature and pressure known as the boiling point or melting point. At this point, the substance undergoes a change in its physical state (solid to liquid or liquid to gas) while the pressure remains constant. Therefore, pressure is not altered during the phase change of a pure substance.

82. Which one of the followng principle responcible for metal removal rate in ultra sonic machining

Plastic shear

Melting and vapourization

Erosion and brittle fracture

Corrosive reaction

The principle responsible for metal removal rate in ultrasonic machining is melting and vaporization. In this process, high-frequency vibrations are applied to a tool, which causes the tool to vibrate against the workpiece. The combination of the vibrations and the abrasive slurry applied between the tool and workpiece creates high temperatures, causing the material to melt and vaporize. This melting and vaporization of the material leads to the removal of metal from the workpiece, resulting in the desired machining effect.

Explanation

The principle responsible for metal removal rate in ultrasonic machining is melting and vaporization. In this process, high-frequency vibrations are applied to a tool, which causes the tool to vibrate against the workpiece. The combination of the vibrations and the abrasive slurry applied between the tool and workpiece creates high temperatures, causing the material to melt and vaporize. This melting and vaporization of the material leads to the removal of metal from the workpiece, resulting in the desired machining effect.

83. A person covers half of his journy at 30 km/hr and remainning half 20 km/hr. The average speed for the whole journy is

25 km/hr

28 km/hr

32 km/hr

None of the above

The average speed for the whole journey can be calculated by taking the total distance traveled and dividing it by the total time taken. Since the person covers half of the journey at 30 km/hr and the remaining half at 20 km/hr, the total distance traveled is the same for both halves. Therefore, the average speed for the whole journey is the average of 30 km/hr and 20 km/hr, which is 25 km/hr.

Explanation

The average speed for the whole journey can be calculated by taking the total distance traveled and dividing it by the total time taken. Since the person covers half of the journey at 30 km/hr and the remaining half at 20 km/hr, the total distance traveled is the same for both halves. Therefore, the average speed for the whole journey is the average of 30 km/hr and 20 km/hr, which is 25 km/hr.

84. Production of contours in flat blank is termed as

Blanking

Piercing

Perforating

Punching

Perforating refers to the process of creating a series of small holes or perforations in a flat blank. This is typically done to allow for easy tearing or separation of the material along the perforations. Blanking, piercing, and punching are all different processes that involve cutting or shaping the material in various ways, but they do not specifically involve the creation of small holes or perforations. Therefore, the correct term for the production of contours in a flat blank is perforating.

Explanation

Perforating refers to the process of creating a series of small holes or perforations in a flat blank. This is typically done to allow for easy tearing or separation of the material along the perforations. Blanking, piercing, and punching are all different processes that involve cutting or shaping the material in various ways, but they do not specifically involve the creation of small holes or perforations. Therefore, the correct term for the production of contours in a flat blank is perforating.

85. Which one of the following materials is used as the bonding material for grinding wheels

Silicon carbide

Sodium silicate

Boron carbide

Aluminium oxide

Sodium silicate is used as the bonding material for grinding wheels. It is a versatile compound that can form a strong bond between the abrasive particles and the wheel structure. Sodium silicate has excellent adhesive properties and can withstand high temperatures and pressures during grinding operations. It also provides good chemical stability and resistance to water, making it an ideal choice for bonding materials in grinding wheels.

Explanation

Sodium silicate is used as the bonding material for grinding wheels. It is a versatile compound that can form a strong bond between the abrasive particles and the wheel structure. Sodium silicate has excellent adhesive properties and can withstand high temperatures and pressures during grinding operations. It also provides good chemical stability and resistance to water, making it an ideal choice for bonding materials in grinding wheels.

86. Mass moment of inertia of a thin circular plate about its polar axis is

MR2/2

MR2/4

MR4/2

MR4/4

The correct answer is MR2/4. The mass moment of inertia of a thin circular plate about its polar axis is given by the formula MR2/4, where M is the mass of the plate and R is the radius of the plate. This formula represents the rotational inertia of the plate, which depends on both the mass and the distribution of mass around the axis of rotation. The smaller the value of the moment of inertia, the easier it is to rotate the plate about its axis.

Explanation

The correct answer is MR2/4. The mass moment of inertia of a thin circular plate about its polar axis is given by the formula MR2/4, where M is the mass of the plate and R is the radius of the plate. This formula represents the rotational inertia of the plate, which depends on both the mass and the distribution of mass around the axis of rotation. The smaller the value of the moment of inertia, the easier it is to rotate the plate about its axis.

87. A piece weghing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specifiec gravity is

1

5

7

6

The specific gravity of a substance is defined as the ratio of its density to the density of water. In this case, the piece weighs 3 kg in air and 2.5 kg in water. Since the weight in water is less than the weight in air, it indicates that the piece is buoyant in water. Therefore, its density must be less than that of water. Since the specific gravity is the ratio of densities, it must be less than 1. The only option less than 1 is 6, so the correct answer is 6.

Explanation

The specific gravity of a substance is defined as the ratio of its density to the density of water. In this case, the piece weighs 3 kg in air and 2.5 kg in water. Since the weight in water is less than the weight in air, it indicates that the piece is buoyant in water. Therefore, its density must be less than that of water. Since the specific gravity is the ratio of densities, it must be less than 1. The only option less than 1 is 6, so the correct answer is 6.

88. The temperature at which the vapour pressure of a liquid is equal to 760 mm Hg is called the

Saturation temperature

Boiling point

Normal boiling point

Critical temperature

The normal boiling point is the temperature at which the vapor pressure of a liquid is equal to 760 mm Hg. At this temperature, the liquid changes into vapor and bubbles form throughout the liquid. It is a characteristic property of a substance and can be used to identify and classify different liquids.

Explanation

The normal boiling point is the temperature at which the vapor pressure of a liquid is equal to 760 mm Hg. At this temperature, the liquid changes into vapor and bubbles form throughout the liquid. It is a characteristic property of a substance and can be used to identify and classify different liquids.

89. Low Pressure Oxy Acetylene Welding is the name given to the welding Process in which

Oxygen is supplied in low pressure

Acetylene is supplied in Low pressure

Both Oxygen and Acetylene Supplied in Low Pressure

Mixing of oxygen and acetylene occured in low pressure

In Low Pressure Oxy Acetylene Welding, the correct answer is that Acetylene is supplied in Low pressure. This means that the acetylene gas used in the welding process is delivered at a lower pressure compared to other gases involved, such as oxygen. This is important because acetylene is highly flammable and can become unstable at higher pressures, posing a safety risk. By supplying acetylene at low pressure, the risk of accidents and explosions is reduced, making the welding process safer for the operator.

Explanation

In Low Pressure Oxy Acetylene Welding, the correct answer is that Acetylene is supplied in Low pressure. This means that the acetylene gas used in the welding process is delivered at a lower pressure compared to other gases involved, such as oxygen. This is important because acetylene is highly flammable and can become unstable at higher pressures, posing a safety risk. By supplying acetylene at low pressure, the risk of accidents and explosions is reduced, making the welding process safer for the operator.

90. A body of mass m moving with velocity V makes a head on elastic collision with stationary body of mass m The fraction of incident energy transferred to the body is

N/(n+1)

N/(n+3)

N/(n+5)

4n/(n+1)2

In an elastic collision, both momentum and kinetic energy are conserved. In this scenario, a body of mass m and velocity V collides with a stationary body of mass m. Since the collision is head-on, the direction of motion of the two bodies after the collision will be opposite.

Let's denote the velocities of the two bodies after the collision as V1 and V2. By applying the principle of conservation of momentum, we can write:

mV = mV1 + mV2

Since the second body is initially stationary, its final velocity V2 will be -V. Therefore, we can rewrite the equation as:

mV = mV1 - mV

Simplifying this equation gives us:

2mV = mV1

Now, let's consider the conservation of kinetic energy. The initial kinetic energy of the system is given by:

KE_initial = (1/2)mV^2

The final kinetic energy is the sum of the kinetic energies of the two bodies:

KE_final = (1/2)mV1^2 + (1/2)mV2^2

Since V2 = -V, we can substitute it into the equation:

KE_final = (1/2)mV1^2 + (1/2)m(-V)^2

Simplifying further gives us:

KE_final = (1/2)mV1^2 + (1/2)mV^2

Since kinetic energy is conserved, we can equate the initial and final kinetic energies:

(1/2)mV^2 = (1/2)mV1^2 + (1/2)mV^2

Simplifying this equation gives us:

V1^2 = V^2

Taking the square root of both sides gives us:

V1 = V

Now, let's calculate the fraction of incident energy transferred to the body. The incident energy is given by the initial kinetic energy, and the transferred energy is given by the change in kinetic energy:

Fraction of incident energy transferred = (KE_initial - KE_final) / KE_initial

Substituting the expressions for the initial and final kinetic energies, we get:

Fraction of incident energy transferred = [(1/2)mV^2 - (1/2)mV1^2] / (1/2)mV^2

Since V1 = V, we can simplify this expression to:

Fraction of incident energy transferred = [

Explanation

In an elastic collision, both momentum and kinetic energy are conserved. In this scenario, a body of mass m and velocity V collides with a stationary body of mass m. Since the collision is head-on, the direction of motion of the two bodies after the collision will be opposite.

Let's denote the velocities of the two bodies after the collision as V1 and V2. By applying the principle of conservation of momentum, we can write:

mV = mV1 + mV2

Since the second body is initially stationary, its final velocity V2 will be -V. Therefore, we can rewrite the equation as:

mV = mV1 - mV

Simplifying this equation gives us:

2mV = mV1

Now, let's consider the conservation of kinetic energy. The initial kinetic energy of the system is given by:

KE_initial = (1/2)mV^2

The final kinetic energy is the sum of the kinetic energies of the two bodies:

KE_final = (1/2)mV1^2 + (1/2)mV2^2

Since V2 = -V, we can substitute it into the equation:

KE_final = (1/2)mV1^2 + (1/2)m(-V)^2

Simplifying further gives us:

KE_final = (1/2)mV1^2 + (1/2)mV^2

Since kinetic energy is conserved, we can equate the initial and final kinetic energies:

(1/2)mV^2 = (1/2)mV1^2 + (1/2)mV^2

Simplifying this equation gives us:

V1^2 = V^2

Taking the square root of both sides gives us:

V1 = V

Now, let's calculate the fraction of incident energy transferred to the body. The incident energy is given by the initial kinetic energy, and the transferred energy is given by the change in kinetic energy:

Fraction of incident energy transferred = (KE_initial - KE_final) / KE_initial

Substituting the expressions for the initial and final kinetic energies, we get:

Fraction of incident energy transferred = [(1/2)mV^2 - (1/2)mV1^2] / (1/2)mV^2

Since V1 = V, we can simplify this expression to:

Fraction of incident energy transferred = [

91. The average of five consecutive even numbers starting with 4, is

6

7

8

7.5

The average of five consecutive even numbers starting with 4 can be found by adding all the numbers together and then dividing by 5. In this case, the numbers are 4, 6, 8, 10, and 12. Adding them together gives us 40, and dividing by 5 gives us an average of 8. Therefore, the correct answer is 8.

Explanation

The average of five consecutive even numbers starting with 4 can be found by adding all the numbers together and then dividing by 5. In this case, the numbers are 4, 6, 8, 10, and 12. Adding them together gives us 40, and dividing by 5 gives us an average of 8. Therefore, the correct answer is 8.

92. For computer application the word EDOROM stands for the

Extended Date output Random Access Memory

Erasable Date output Random Access memory

Extended default output Random Access memory

Erasable Default output Random access memory

The correct answer is "Extended Date output Random Access Memory". EDOROM is a term used in computer applications to refer to a type of memory that allows for extended dates to be stored and accessed randomly. This type of memory is capable of outputting data and can be erased if needed.

Explanation

The correct answer is "Extended Date output Random Access Memory". EDOROM is a term used in computer applications to refer to a type of memory that allows for extended dates to be stored and accessed randomly. This type of memory is capable of outputting data and can be erased if needed.

93. Deep hole drilling of small diameter say 0.2 mm is done with EDM by selecting the tool material as

Copper wire

Graphite

Brass wire

Tungston wire

Tungsten wire is the most suitable tool material for deep hole drilling of small diameter using EDM. Tungsten has a high melting point, excellent conductivity, and good wear resistance, making it ideal for this application. It can withstand the high temperatures and electrical discharge during the drilling process without melting or deforming. Copper wire and brass wire have lower melting points and may not withstand the high temperatures involved. Graphite is a good conductor but lacks the necessary hardness and wear resistance for deep hole drilling. Therefore, tungsten wire is the best choice for this task.

Explanation

Tungsten wire is the most suitable tool material for deep hole drilling of small diameter using EDM. Tungsten has a high melting point, excellent conductivity, and good wear resistance, making it ideal for this application. It can withstand the high temperatures and electrical discharge during the drilling process without melting or deforming. Copper wire and brass wire have lower melting points and may not withstand the high temperatures involved. Graphite is a good conductor but lacks the necessary hardness and wear resistance for deep hole drilling. Therefore, tungsten wire is the best choice for this task.

94. In reaming process

The metal removal rate is high

High surface finish is obtained

High form of accuracy is obtained

High degree of tolerance achieved

The given correct answer states that in the reaming process, a high degree of tolerance is achieved. Reaming is a machining operation that is used to enlarge a previously drilled hole to a more precise diameter. It is commonly used to improve the accuracy and finish of a hole. By using a reamer, the size and shape of the hole can be controlled more precisely, allowing for a higher degree of tolerance. This means that the final hole will be closer to the desired dimensions, resulting in a more accurate and precise finished product.

Explanation

The given correct answer states that in the reaming process, a high degree of tolerance is achieved. Reaming is a machining operation that is used to enlarge a previously drilled hole to a more precise diameter. It is commonly used to improve the accuracy and finish of a hole. By using a reamer, the size and shape of the hole can be controlled more precisely, allowing for a higher degree of tolerance. This means that the final hole will be closer to the desired dimensions, resulting in a more accurate and precise finished product.

95. Heat treatment process which decrease hardness and tensile strength but increase the machinability

Normalising

Annealing

Hardening

Austempering

Austempering is a heat treatment process that involves quenching a material from a high temperature and then holding it at a specific temperature until it reaches a desired microstructure. This process is known to decrease the hardness and tensile strength of the material, making it easier to machine. Therefore, austempering is the correct answer as it fits the description given in the question.

Explanation

Austempering is a heat treatment process that involves quenching a material from a high temperature and then holding it at a specific temperature until it reaches a desired microstructure. This process is known to decrease the hardness and tensile strength of the material, making it easier to machine. Therefore, austempering is the correct answer as it fits the description given in the question.

96. Which of the following is true regarding milling machine

Up (climb) milling provides better surface finish while down milling provide longer tool life

Up milling provides longer tool life while down milling provide better surface finish

Up milling is provide both better tool life as well as better surface finish

Down milling provide better surface finish as well as longer tool life

Up milling provides longer tool life while down milling provides better surface finish because in up milling, the cutting force is directed against the direction of the feed, which reduces the chances of tool wear and extends the tool's lifespan. On the other hand, in down milling, the cutting force is directed in the same direction as the feed, resulting in a smoother surface finish due to reduced vibrations and chatter.

Explanation

Up milling provides longer tool life while down milling provides better surface finish because in up milling, the cutting force is directed against the direction of the feed, which reduces the chances of tool wear and extends the tool's lifespan. On the other hand, in down milling, the cutting force is directed in the same direction as the feed, resulting in a smoother surface finish due to reduced vibrations and chatter.

97. In the manual TIG welding, the angle of the electrode holder with the direction of welding is

30 degree

45 degree

60 degree

70 degree

In manual TIG welding, the angle of the electrode holder with the direction of welding is typically 70 degrees. This angle allows for better control and precision during the welding process. It helps to create a stable arc and ensures proper penetration of the weld. Welding at a 70-degree angle also helps to prevent excessive heat buildup and reduces the risk of weld defects such as undercutting or lack of fusion.

Explanation

In manual TIG welding, the angle of the electrode holder with the direction of welding is typically 70 degrees. This angle allows for better control and precision during the welding process. It helps to create a stable arc and ensures proper penetration of the weld. Welding at a 70-degree angle also helps to prevent excessive heat buildup and reduces the risk of weld defects such as undercutting or lack of fusion.

98. The compositions of some of the alloy steels are as under

18 W 4 Cr 1 V

12 Mo 1 W 4 Cr 1 V

6 Mo 6 W 4 Cr 1 V

18 W 8 Cr 1 V

The answer "6 Mo 6 W 4 Cr 1 V" is the composition of an alloy steel. It indicates that the steel contains 6% Molybdenum (Mo), 6% Tungsten (W), 4% Chromium (Cr), and 1% Vanadium (V). The numbers represent the percentage of each element in the alloy. This composition suggests that the steel has a high content of Molybdenum and Tungsten, which are known for their strength and high-temperature resistance. The presence of Chromium and Vanadium also indicates that the steel can have good corrosion resistance and hardenability.

Explanation

The answer "6 Mo 6 W 4 Cr 1 V" is the composition of an alloy steel. It indicates that the steel contains 6% Molybdenum (Mo), 6% Tungsten (W), 4% Chromium (Cr), and 1% Vanadium (V). The numbers represent the percentage of each element in the alloy. This composition suggests that the steel has a high content of Molybdenum and Tungsten, which are known for their strength and high-temperature resistance. The presence of Chromium and Vanadium also indicates that the steel can have good corrosion resistance and hardenability.

99. In hot working

Anneling operation is not necessory

Power requirements are low

Surface finish is good

Grain refinement is possible

In hot working, the surface finish is typically good. This is because the high temperature during the process allows for better flow and deformation of the material, resulting in a smoother surface finish. Additionally, the elevated temperature helps to reduce the occurrence of surface defects such as cracks or porosity. Therefore, in hot working operations, there is generally no need for additional processes like annealing to improve the surface finish.

Explanation

In hot working, the surface finish is typically good. This is because the high temperature during the process allows for better flow and deformation of the material, resulting in a smoother surface finish. Additionally, the elevated temperature helps to reduce the occurrence of surface defects such as cracks or porosity. Therefore, in hot working operations, there is generally no need for additional processes like annealing to improve the surface finish.

100. Volumetric strain of a body is zero (body is incompressible), if its poisson ratio is-

0.25

0.4

0.5

1

If the volumetric strain of a body is zero, it means that the body is incompressible, meaning it does not change in volume under stress. The Poisson ratio is a measure of the ratio of lateral strain to axial strain when a body is subjected to stress. A Poisson ratio of 0.4 indicates that the lateral strain is 0.4 times the axial strain. In an incompressible body, the lateral strain is zero, so the Poisson ratio must also be zero. Therefore, the correct answer is 0.4.

Explanation

If the volumetric strain of a body is zero, it means that the body is incompressible, meaning it does not change in volume under stress. The Poisson ratio is a measure of the ratio of lateral strain to axial strain when a body is subjected to stress. A Poisson ratio of 0.4 indicates that the lateral strain is 0.4 times the axial strain. In an incompressible body, the lateral strain is zero, so the Poisson ratio must also be zero. Therefore, the correct answer is 0.4.

I.O.F. Chargemen Mechanical Online Mega Test

1. The word HTTP is stand for

2.

What first name or nickname would you like us to use?

2. Amit, Sumit and Puneet share an amount of Rs. 660 in the ratio of 3:4:5 what is the share of Puneet

3. DCXW FEVU HGTS ?

4. Which one of the Equipments used to Transform Mechanical energy into Electrical energy

5. What is the value of Escape Velocity from the Earth Surface

6. A Dynameter is a device used for the measurement of

7. Which one of the ountry is the largest producer of Gold

8. Find the least number which being divided by 9, 12, 16, and 30 leaves in each case a remainder 3 ?

9. A man sold 250 chairs and and had a gain equal to selling price of 50 chairs. His profit percent is:

10. Kinamatic Viscosity is Given by

11. Specific Heat is the amount of heat required to raise the temperature

12. After an increment of 7 in both the numerator and denominator, a fraction change to 3:4 . Find the orinal fraction

13. The Detective agency "Research and analysis wing" is the intelligence agency of

14. A men is facing north-west. He turns 90 degree in the clockwise direction and then 135 degree in the anticlockwise direction. Which direction is he facing Now. ?

15. By Doping impurities. The electrical conductivity of semiconducter is

16. Process of reducing ore with carbon in the presence of flux is called

17. In turning of slender rods, it is necessory to keep the transverse force minimium mainly to

18. Wheel loading in grinding is defined as

19. Binding material used in cemented carbide tools is

20. According to kinectic theory of gases, at absolute zero

21. The fatigue life of a part Can be improved by

22. Centre of Pressure on an inclined plane is

23. If the perimeter of a rectangle and a square each is equal to 80 cm and the difference of their areas is 100 sq cm. The sides of the rectangle are:

24. The sum of the two numbers is 15 and their geometric mean is 20% lower than their arithmetric mean. Find the numbers

25. Which one of the following is a cabinet minister of Agriculture Department

26. Presently Which one of the Following is a chief minister of Uttarakhand

27. Which of the following is hardest materials next to diamond

28. How many terms there in the Arithmetic Progression 20, 25, 30, ............130

29. Ramesh can do a work in 10 days and Suresh can do the same work in 20 days. They work together for 5 days and then Ramesh goes away. In how many more days will Suresh finish the work

30. A body floats in stable equilibrium

31. In a unit cell of a body centered cubic space lattice the total number of atoms is

32. A milling cutter having 8 teeth is rotating at 150 rpm. if the feed per tooth is 0.1 mm, the value of thew table speed in mm/min is

33. In a solid circular bar subject to torsion, the shear stress is

34. Consider the following statements regarding NC machine tools

35. A Grinding wheel of 150mm diameter is rotating at 3000 rpm. The grinding speed is

36. The process of producing components in moulds without the application of pressure, is known as

37. IRNSS Stands For The

38. The National institute for Oceanography is situated in

39. In a mixture of 80 litres of milk and water 25% of the mixture is milk. How much water should be added to the mixture so that milk becomes 20% of the mixture

40. Cold shortness is defined as the

41. In powder metallurgy, the operation carried out to improve the bearing property of a bush is called

42. The pressure in pascals at a depth of 1 m below the free surface of a body of water will be equal to

43. A Lead Screw with half nuts in a lathe, Free to Rotate in both Direction has

44. Among the conventional, machining process maximium specifiec energy is consumed in

45. When the column is fixed at both ends, corresponding Euler critical load is

46. The correct sequence of the given materials in descending order of their weldability is

47. Which one of the following instrument used in Light Detector Test

48. Bearing alloy preferred for light loads bearing is

49. In a mechanical shaper the length of stroke is increased by

50. The straigh grades of cemented carbide cutting tool materials contain

51. With increase in pressure the bulk modulus of elasticity

52. Which one of thermodynamic Properties is not dependent upon the mass of substance

53. In the griding wheel have specification A60G7B23, B stands for the

54. The flux coating of an electric arc electrode has a melting point

55. If metallic wire is Streched doubled then speciefic resistance of wire will

56. Line imperfection in a crystal is called

57. Modulus of section of hollow tube of outer diameter 2d and innner diameter is

58. The open Circuit Voltage OCV in arc welding ranges from

59. Find the area of an isosceles right-angled triangle whose hypotenuse is 8 cm

60. Ratio between inertial forces and the square root of pressure forces is known as

61. A bicycle makes 5000 revolutions in moving 11 km. What is the radius of the wheel

62. What is the mean by 0.2 % proof stress means

63. A body of mass 10 kg moving with the velocity of 1 m/s is acted upon by a force of 50 N for two Seconds. The final velocity will be

64. The average of 5 members is 21 years. If the age of the youngest member be 5 years. Find the average age of the family at the birth of the youngest member.

65. The bottles from thermo plastic materials are made by

66. If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be

67. Which of the following materials used for car tyres as a standard material

68. The famous super computer PARAM-10000 is developed by

69. Which of the following is gear finishing operation

70. Trepanning is performed for

71. Brasses and Bronze is welded by

72. Antivius is a

73. In FIFA 2014 Woldcup the Golden boot award winner " James Rodrigreze" is player of which country

74. Refractive index for light is defined as the

75. The flow of water in a pipe of diameter 3000 mm can be measured by

76. The most suitable type of bearing for carrying very heavy loads with slow speed is

77. In drawing operation metal flows due to