Cameron Company Mock Placement
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Questions and Answers
- 1.
Which of the following is a mechanism for mechanized movements of the carriage along longitudinal axis?
- A.
Cross-slide
- B.
Compound rest
- C.
Apron
- D.
Saddle
Correct Answer
C. ApronExplanation
The apron is a mechanism that allows for the mechanized movement of the carriage along the longitudinal axis. It is located at the front of the carriage and is responsible for engaging with the lead screw, which in turn moves the carriage along the length of the lathe bed. The apron also houses various controls and mechanisms for controlling the feed rate and direction of the carriage movement. The other options mentioned (cross-slide, compound rest, and saddle) are not specifically designed for the longitudinal movement of the carriage.Rate this question:
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- 2.
The function of taper turning process is to ____
- A.
Reduce the diameter of a workpiece along its length
- B.
reduce the diameter by removing material about an axis offset from the axis of workpiece
- C.
Remove the material from end surface of a workpiece
- D.
All of the above
Correct Answer
B. reduce the diameter by removing material about an axis offset from the axis of workpieceExplanation
The correct answer is "reduce the diameter by removing material about an axis offset from the axis of workpiece." Taper turning is a process used to gradually decrease the diameter of a workpiece along its length. This is achieved by removing material from the workpiece in a manner that follows a tapering shape, with an axis offset from the original axis of the workpiece. This process allows for the creation of tapered surfaces or shapes on the workpiece.Rate this question:
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- 3.
The process of bevelling sharp ends of a workpiece is called as ________
- A.
Knurling
- B.
Grooving
- C.
Facing
- D.
Chamfering
Correct Answer
D. ChamferingExplanation
Chamfering is the process of beveling the sharp ends of a workpiece. This is done to create a sloping edge or surface, usually at a 45-degree angle, which helps to prevent injury and make the workpiece safer to handle. It is commonly used in woodworking, metalworking, and other industries where sharp edges need to be smoothed or removed. Knurling is a process of creating a patterned texture on a workpiece, grooving refers to creating a groove or channel, and facing involves creating a flat surface on the end of a workpiece.Rate this question:
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- 4.
In an isolated system, ________ can be transferred between the system and its surrounding.
- A.
Only energy
- B.
Only mass
- C.
Both energy and mass
- D.
Neither energy nor mass
Correct Answer
D. Neither energy nor massExplanation
In an isolated system, neither energy nor mass can be transferred between the system and its surroundings. This means that the total amount of energy and mass within the system remains constant. In other words, there is no exchange of energy or mass with the surroundings in an isolated system.Rate this question:
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- 5.
Which of the following is an extensive property?
- A.
Volume
- B.
Pressure
- C.
Viscosity
- D.
All of the above
Correct Answer
A. VolumeExplanation
Volume is an extensive property because it depends on the amount of substance present. It is a measure of the space occupied by an object or substance and can be added or subtracted when substances are combined or separated. In contrast, pressure and viscosity are intensive properties as they do not depend on the amount of substance present.Rate this question:
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- 6.
How is absolute pressure measured?
- A.
Gauge pressure + Atmospheric pressure
- B.
Gauge pressure – Atmospheric pressure
- C.
Gauge pressure / Atmospheric pressure
- D.
None of the above
Correct Answer
A. Gauge pressure + Atmospheric pressureExplanation
Absolute pressure is measured by adding the gauge pressure to the atmospheric pressure. Gauge pressure is the pressure measured by a pressure gauge, which is relative to the atmospheric pressure. By adding the atmospheric pressure to the gauge pressure, the absolute pressure can be determined.Rate this question:
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- 7.
An isobaric process, has constant _____
- A.
Density
- B.
Pressure
- C.
Temperature
- D.
Volume
Correct Answer
B. PressureExplanation
In an isobaric process, the pressure remains constant. This means that the system is experiencing a change in other variables, such as temperature or volume, while the pressure remains the same. Isobaric processes often occur when there is a constant external pressure acting on the system.Rate this question:
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- 8.
Which of the following energy conversion devices convert heat into work?
- A.
Electrical generators
- B.
I. C engines
- C.
Condensers
- D.
All of the above
Correct Answer
B. I. C enginesExplanation
I. C engines convert heat into work by using the combustion of fuel to create high-pressure gases that push pistons, which in turn generate mechanical work. Electrical generators, on the other hand, convert mechanical work into electrical energy. Condensers are used to convert steam into liquid form by removing heat from the steam. Therefore, the correct answer is I. C engines.Rate this question:
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- 9.
In four stroke cycle engine, cycle is completed in ______
- A.
Two strokes of the piston
- B.
Two revolutions of the crankshaft
- C.
Three strokes of the piston
- D.
Four revolutions of the crankshaft
Correct Answer
B. Two revolutions of the crankshaftExplanation
In a four-stroke cycle engine, the cycle is completed in two revolutions of the crankshaft. This is because each stroke of the piston (intake, compression, power, exhaust) requires one revolution of the crankshaft to complete. Therefore, in a complete cycle, the piston goes through these four strokes and the crankshaft rotates twice to accommodate them.Rate this question:
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- 10.
Determine torque transmitted on the pinion shaft if torque transmitted on gear shaft is 20 Nm. Consider Gear ratio = 4
- A.
8 Nm
- B.
5 Nm
- C.
80 Nm
- D.
16 Nm
Correct Answer
B. 5 NmExplanation
The torque transmitted on the pinion shaft can be determined using the gear ratio. The gear ratio is the ratio of the number of teeth on the pinion gear to the number of teeth on the gear. In this case, the gear ratio is given as 4. Since the torque transmitted on the gear shaft is 20 Nm, the torque transmitted on the pinion shaft can be calculated by dividing the torque on the gear shaft by the gear ratio. Therefore, 20 Nm divided by 4 is equal to 5 Nm.Rate this question:
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- 11.
Deformation per unit length is called as ________
- A.
Strain
- B.
Stress
- C.
Modulus of elasticity
- D.
None of the above
Correct Answer
A. StrainExplanation
Strain is the correct answer because it refers to the deformation per unit length. When an object undergoes deformation, the change in length or shape is measured as strain. It is a measure of how much an object has been stretched or compressed compared to its original length. Strain is typically expressed as a decimal or percentage. Stress, on the other hand, refers to the force applied per unit area and is not the same as deformation per unit length. Modulus of elasticity is a measure of a material's stiffness and is not directly related to deformation per unit length.Rate this question:
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- 12.
Which of the following materials do not have a well defined yield point?
- A.
Heat treated steel
- B.
Concrete
- C.
Carbon fiber
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
All of the materials mentioned in the options, namely heat treated steel, concrete, and carbon fiber, do not have a well-defined yield point. A yield point is a stress level at which a material begins to deform plastically, meaning it undergoes permanent deformation even after the removal of the applied stress. Heat treated steel, concrete, and carbon fiber all exhibit different behaviors when subjected to stress, but none of them have a distinct yield point. Instead, they may show gradual or non-linear deformation patterns under increasing stress.Rate this question:
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- 13.
Factor of safety is the ratio of _________
- A.
Working stress and ultimate strength
- B.
Yield strength and endurance strength
- C.
Ultimate strength and yield strength
- D.
Yield strength and working stress
Correct Answer
B. Yield strength and endurance strengthExplanation
Factor of safety is the ratio between the yield strength and the endurance strength. The yield strength is the maximum stress that a material can withstand without permanent deformation, while the endurance strength is the maximum stress that a material can withstand without failure over a large number of cycles. By comparing these two strengths, the factor of safety determines the margin of safety in a design, ensuring that the material can handle the applied stress and prevent failure.Rate this question:
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- 14.
The elongation of a bar is 0.5 mm when a tensile stress of 200 N/mm2 acts on it. Determine the original length of a bar if the modulus of elasticity is 150 x 103.
- A.
375.93 mm
- B.
300 mm
- C.
360 mm
- D.
None of the above
Correct Answer
A. 375.93 mmExplanation
The elongation of a bar can be calculated using the formula: elongation = (stress * length) / (modulus of elasticity). Rearranging the formula to solve for length, we have: length = (elongation * modulus of elasticity) / stress. Plugging in the given values, we get: length = (0.5 mm * 150 x 10^3) / 200 N/mm2 = 375.93 mm. Therefore, the original length of the bar is 375.93 mm.Rate this question:
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- 15.
Which of the following statements is/are true for alloy steels?
- A.
They contain carbon more than 1.7%
- B.
They are ductile
- C.
They have low resilience and toughness
- D.
All of the above
Correct Answer
B. They are ductileExplanation
Alloy steels are known to be ductile, meaning they can be easily stretched without breaking. This property is due to the presence of various alloying elements, such as nickel, chromium, and manganese, which enhance the steel's ability to deform without fracturing. Ductility is an important characteristic in many applications, as it allows the material to be formed into different shapes and withstand deformation without failure. Therefore, the statement "They are ductile" is true for alloy steels.Rate this question:
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- 16.
Which of the following is a ferrous alloy?
- A.
Brass
- B.
Aluminum alloys
- C.
Cast steel
- D.
All of the above
Correct Answer
C. Cast steelExplanation
Cast steel is a ferrous alloy because it is primarily composed of iron with carbon and other elements added to enhance its properties. Ferrous alloys are those that contain iron as the main constituent, and cast steel fits this criterion as it is made by melting iron and adding carbon and other alloying elements before casting it into a desired shape. Brass and aluminum alloys, on the other hand, are non-ferrous alloys as they do not contain iron as the main component.Rate this question:
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- 17.
Copper, when alloyed with zinc, is known as
- A.
Brass
- B.
Bronze
- C.
Babbits
- D.
All of the above
Correct Answer
A. BrassExplanation
Copper, when alloyed with zinc, is known as brass. Brass is a commonly used alloy that is known for its yellowish color and high malleability. It is often used in musical instruments, plumbing fixtures, and decorative items. Bronze, on the other hand, is an alloy of copper and tin, while babbits is a type of bearing alloy. Therefore, the correct answer is brass.Rate this question:
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- 18.
What is meant by drag in the casting process?
- A.
Upper part of casting flask
- B.
Molten metal
- C.
Lower part of casting flask
- D.
Upper and lower part of casting flask
Correct Answer
C. Lower part of casting flaskExplanation
In the casting process, the term "drag" refers to the lower part of the casting flask. The casting flask is a container used to hold the mold during the casting process. It is typically made up of two parts - the drag and the cope. The drag is the bottom part of the flask, while the cope is the top part. The drag is responsible for holding the bottom half of the mold, which is where the molten metal is poured into. Therefore, the correct answer is the lower part of the casting flask.Rate this question:
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- 19.
Casting replica used to make the cavity is called as
- A.
Mould
- B.
Pattern
- C.
Cope
- D.
None of the above
Correct Answer
B. PatternExplanation
The correct answer is "Pattern." In casting, a pattern is used to create a replica or model of the desired object. This pattern is then used to make the cavity in the mold, which is filled with molten material to create the final product. Therefore, a casting replica used to make the cavity is called a pattern.Rate this question:
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- 20.
The process of joining similar or dissimilar materials by heating them below 450o C using non-ferrous filler material is called as ______
- A.
Brazing
- B.
Welding
- C.
Soldering
- D.
All of the above
Correct Answer
C. SolderingExplanation
Soldering is the process of joining similar or dissimilar materials by heating them below 450o C using non-ferrous filler material. This process involves melting the filler material, known as solder, and applying it to the joint, where it solidifies and forms a bond between the materials. Unlike welding, soldering does not require the base materials to be melted, making it suitable for delicate or heat-sensitive components. Brazing is a similar process, but it involves heating the materials to a higher temperature, typically above 450o C. Therefore, the correct answer is soldering.Rate this question:
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- 21.
At forging temperature when a compressive force is applied on the material, it deforms
- A.
elastically in the direction of least resistance
- B.
Elastically in the direction of maximum resistance
- C.
Plastically in the direction of least resistance
- D.
Plastically in the direction of maximum resistance
Correct Answer
A. elastically in the direction of least resistanceExplanation
When a compressive force is applied on a material at forging temperature, it deforms elastically in the direction of least resistance. This means that the material will temporarily change shape under the applied force, but it will return to its original shape once the force is removed. The direction of least resistance refers to the path that offers the least resistance to the applied force, causing the material to deform in that direction. This elastic deformation is reversible and does not result in a permanent change in the material's shape.Rate this question:
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- 22.
Which process squeezes metals into peaks and troughs with plastic deformation?
- A.
Grooving
- B.
Knurling
- C.
Reaming
- D.
None of the above
Correct Answer
B. KnurlingExplanation
Knurling is a process that involves squeezing metals into peaks and troughs with plastic deformation. It is commonly used to create a pattern on the surface of a workpiece, providing better grip and texture. Grooving, reaming, and none of the above do not involve the same type of deformation as knurling, making them incorrect options.Rate this question:
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- 23.
Which of the following operations is/are performed on a lathe machine?
- A.
Spot-facing
- B.
Parting
- C.
Reaming
- D.
All of the above
Correct Answer
B. PartingExplanation
Parting is a machining operation performed on a lathe machine. It involves cutting a workpiece into two separate parts by using a narrow cutting tool called a parting tool. This operation is commonly used to create grooves, cut off excess material, or separate the workpiece into multiple sections. Spot-facing and reaming, on the other hand, are not typically performed on a lathe machine. Spot-facing is usually done on milling machines, while reaming is a drilling operation. Therefore, the correct answer is parting as it is the only operation mentioned that is performed on a lathe machine.Rate this question:
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- 24.
On drilling machine, which process is known as reaming?
- A.
Enlargement of existing hole
- B.
Hole made by removal of metal along the hole circumference
- C.
Smoothly finishing and accurately sizing a drilled hole
- D.
All of the above
Correct Answer
C. Smoothly finishing and accurately sizing a drilled holeExplanation
Reaming is the process on a drilling machine that involves smoothly finishing and accurately sizing a drilled hole. This process is used to remove any burrs or rough edges left behind from the drilling operation and to ensure that the hole has the correct dimensions. Reaming helps to improve the surface finish and accuracy of the hole, making it suitable for various applications.Rate this question:
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- 25.
The radiation pyrometers work on the principle of _____
- A.
Newton’s law
- B.
Stefan Boltzmann’s law
- C.
Zeroth law
- D.
None of the above
Correct Answer
B. Stefan Boltzmann’s lawExplanation
Radiation pyrometers work on the principle of Stefan Boltzmann's law, which states that the total radiant heat energy emitted by a black body is proportional to the fourth power of its absolute temperature. This law allows the pyrometer to measure the temperature of an object by measuring the intensity of the infrared radiation it emits. Newton's law and the zeroth law are not applicable to the principle of radiation pyrometers.Rate this question:
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- 26.
According to Joule’s law, the internal energy of a perfect gas is the function of absolute ______
- A.
Density
- B.
Pressure
- C.
Temperature
- D.
Volume
Correct Answer
C. TemperatureExplanation
According to Joule's law, the internal energy of a perfect gas is directly proportional to its temperature. This means that as the temperature of a perfect gas increases, its internal energy also increases. Therefore, temperature is the correct answer in this case.Rate this question:
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- 27.
According to Kelvin-Planck statement, it is impossible to construct a device operating on a cycle which transfers heat from ____
- A.
Low pressure heat reservoir to high pressure reservoir
- B.
Low temperature heat reservoir to high temperature reservoir
- C.
High pressure heat reservoir to low pressure reservoir
- D.
high temperature heat reservoir to low temperature reservoir
Correct Answer
B. Low temperature heat reservoir to high temperature reservoirExplanation
According to the Kelvin-Planck statement, it is impossible to construct a device operating on a cycle that transfers heat from a low temperature heat reservoir to a high temperature reservoir. This statement is based on the principle of the second law of thermodynamics, which states that heat cannot spontaneously flow from a colder body to a hotter body without the aid of external work being done on the system. This is because heat naturally flows from a higher temperature to a lower temperature, and it requires work input to reverse this natural flow.Rate this question:
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- 28.
Which of the following relations is true, for the coefficient of performance (C.O.P)?
- A.
(C.O.P)heat pump – (C.O.P)refrigerator = 1
- B.
(C.O.P)heat pump – (C.O.P)refrigerator > 1
- C.
(C.O.P)heat pump – (C.O.P)refrigerator < 1
- D.
(C.O.P)heat pump – ( C.O.P)refrigerator = 0
Correct Answer
A. (C.O.P)heat pump – (C.O.P)refrigerator = 1Explanation
The correct answer is (C.O.P)heat pump - (C.O.P)refrigerator = 1. This means that the coefficient of performance for a heat pump minus the coefficient of performance for a refrigerator is equal to 1.Rate this question:
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- 29.
Thermal efficiency of S.I. engines is low, due to ____
- A.
low compression ratio
- B.
high compression ratio
- C.
Medium compression ratio
- D.
None
Correct Answer
A. low compression ratioExplanation
The thermal efficiency of S.I. engines is low due to the low compression ratio. A low compression ratio means that the air-fuel mixture is not compressed as much before ignition, leading to incomplete combustion and lower efficiency. Higher compression ratios allow for better combustion and therefore higher thermal efficiency. Medium or high compression ratios would result in better efficiency, but the given answer specifically states that the thermal efficiency is low due to a low compression ratio.Rate this question:
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- 30.
Which of the following protects penstock due to sudden variation of flow or velocity of water?
- A.
Anchors
- B.
Forebays
- C.
Trash rack
- D.
Surge tank
Correct Answer
D. Surge tankExplanation
A surge tank is designed to protect penstock, which is a pipe that carries water to a hydropower turbine, from sudden variations in flow or velocity of water. When there is a sudden increase in flow or velocity, the surge tank acts as a buffer, absorbing the excess pressure and preventing damage to the penstock. This helps to maintain a stable flow of water to the turbine and ensures the efficient operation of the hydropower system.Rate this question:
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- 31.
Forces are called concurrent when their lines of action meet in
- A.
One point
- B.
Two points
- C.
Plane
- D.
Perpendicular planes
Correct Answer
A. One pointExplanation
Concurrent forces are defined as forces that act on a common point or have their lines of action intersecting at a single point. This means that the forces are applied from different directions but meet at a single point, resulting in a combined effect at that point. Therefore, the correct answer is "one point".Rate this question:
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- 32.
If two equal forces of magnitude P act at an angle 9°, their resultant will be_______
- A.
P/2 cos 9/2
- B.
P sin 9/2
- C.
2P tan 9/2
- D.
P cos (9/2)
Correct Answer
D. P cos (9/2)Explanation
When two equal forces of magnitude P act at an angle of 9°, their resultant can be found using the cosine rule. The cosine rule states that the square of the resultant is equal to the sum of the squares of the individual forces plus twice the product of the forces and the cosine of the angle between them. In this case, since the forces are equal, the cosine of the angle is equal to 1. Therefore, the resultant is equal to P cos (9/2).Rate this question:
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- 33.
A body moves, from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly
- A.
38 m
- B.
62.5 m
- C.
96 m
- D.
124 m
Correct Answer
B. 62.5 mExplanation
The distance covered by a body with constant acceleration can be calculated using the equation: distance = (initial velocity * time) + (0.5 * acceleration * time^2). In this case, the body starts from rest, so the initial velocity is 0. The time is given as 5 seconds, and the acceleration is given as 5 m/s^2. Plugging these values into the equation, we get: distance = (0 * 5) + (0.5 * 5 * 5^2) = 0 + (0.5 * 5 * 25) = 0 + 62.5 = 62.5 m. Therefore, the correct answer is 62.5 m.Rate this question:
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- 34.
A cable with a uniformly distributed load per horizontal meter run will take the following shape
- A.
Straight line
- B.
Parabola
- C.
Hyperbola
- D.
Part of a circle.
Correct Answer
B. ParabolaExplanation
A cable with a uniformly distributed load per horizontal meter run will take the shape of a parabola. This is because the weight of the cable causes it to sag under its own weight, and the force of gravity acts uniformly along the length of the cable. The shape of a parabola is formed when an object is subject to a downward force and is supported at two points, resulting in a curved shape. Therefore, a cable with a uniformly distributed load per horizontal meter run will naturally form a parabolic shape.Rate this question:
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- 35.
Which type of body is an airfoil?
- A.
Streamline body
- B.
Wave body
- C.
Bluff body
- D.
induced body
Correct Answer
A. Streamline bodyExplanation
An airfoil is a type of body that is designed to generate lift when it moves through the air. It is characterized by its streamlined shape, which allows for smooth airflow over the surface. This streamlined shape helps to reduce drag and increase the efficiency of the airfoil. Therefore, the correct answer is "streamline body" as it accurately describes the type of body that is an airfoil.Rate this question:
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- 36.
The body whose surface does not coincide with the streamline when places in a flow is called as
- A.
Streamline body
- B.
Wave body
- C.
Bluff body
- D.
Induced body
Correct Answer
C. Bluff bodyExplanation
A bluff body refers to a body whose surface does not align with the streamline when placed in a flow. Unlike a streamlined body, which has a smooth and streamlined shape that minimizes drag, a bluff body has a non-streamlined shape that creates turbulence and increases drag. This term is commonly used in fluid dynamics to describe objects such as cylinders, spheres, or cubes that have a high drag coefficient due to their shape.Rate this question:
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- 37.
When is a liquid said to be not in a boiling or vaporized state?
- A.
If the pressure on liquid is equal to its vapour pressure
- B.
If the pressure on liquid is less than its vapour pressure
- C.
If the pressure on liquid is more than its vapour pressure
- D.
Unpredictable
Correct Answer
C. If the pressure on liquid is more than its vapour pressureExplanation
When the pressure on a liquid is greater than its vapor pressure, the liquid is not in a boiling or vaporized state. This is because vapor pressure is the pressure exerted by the vapor molecules above the liquid when the liquid and vapor are in equilibrium. When the external pressure is higher than the vapor pressure, the liquid molecules are unable to escape and transition into the vapor phase, thus remaining in a liquid state.Rate this question:
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- 38.
One litre of a certain fluid weighs 8N. What is its specific volume?
- A.
2.03 x 10– 3 m3/kg
- B.
20.3 x 10– 3 m3/kg
- C.
20.3 x 10– 3 m3/kg
- D.
1.23 x 10– 3 m3/kg
Correct Answer
D. 1.23 x 10– 3 m3/kgExplanation
The specific volume of a substance is defined as the volume occupied by one unit mass of the substance. In this question, we are given that one liter of the fluid weighs 8N. Since weight is equal to mass multiplied by acceleration due to gravity, we can calculate the mass of the fluid as 8N divided by the acceleration due to gravity. The specific volume is then calculated by dividing the volume (1 liter) by the mass of the fluid. Therefore, the specific volume is 1.23 x 10– 3 m3/kg.Rate this question:
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- 39.
According to Archimede’s principle, if a body is immersed partially or fully in a fluid then the buoyancy force is _______ the weight of fluid displaced by the body.
- A.
Equal to
- B.
Less than
- C.
More than
- D.
Unpredictable
Correct Answer
A. Equal toExplanation
According to Archimedes' principle, the buoyancy force experienced by a body immersed in a fluid is equal to the weight of the fluid displaced by the body. This means that the upward force exerted on the body by the fluid is equal to the downward force of gravity on the fluid displaced.Rate this question:
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- 40.
What is the effect on quality of the energy when it is conserved?
- A.
The quality of the energy increases while conserving its quantity
- B.
The quality of the energy decreases while conserving its quantity
- C.
the quality of the energy remains same while conserving its quantity
- D.
None of the above
Correct Answer
B. The quality of the energy decreases while conserving its quantityExplanation
When energy is conserved, the quantity of energy remains the same, but the quality decreases. This means that while the total amount of energy is preserved, it may become less useful or less concentrated. Conservation of energy often involves transformations or conversions that result in a less concentrated or lower quality form of energy. Therefore, the quality of the energy decreases while conserving its quantity.Rate this question:
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- 41.
A pure substance exists in
- A.
solid phase
- B.
Liquid phase
- C.
Gaseous phase
- D.
all of the above
Correct Answer
D. all of the aboveExplanation
A pure substance can exist in all three phases - solid, liquid, and gaseous. The phase in which a substance exists depends on the temperature and pressure conditions. At low temperatures and high pressures, a pure substance exists in the solid phase, where the particles are closely packed together. As the temperature increases, the substance transitions into the liquid phase, where the particles are less closely packed and can move around more freely. At even higher temperatures, the substance transitions into the gaseous phase, where the particles are far apart and have high energy. Therefore, a pure substance can exist in all of these phases depending on the conditions.Rate this question:
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- 42.
What is a mole of a substance?
- A.
One mole has a mass numerically equal to half the molecular weight of the substance
- B.
One mole has a mass numerically equal to the molecular weight of the substance
- C.
One mole has a mass numerically equal to double the molecular weight of the substance
- D.
none of the above
Correct Answer
B. One mole has a mass numerically equal to the molecular weight of the substanceExplanation
A mole of a substance is a unit of measurement used in chemistry to represent a certain amount of that substance. The mass of one mole of a substance is numerically equal to its molecular weight. This means that if you know the molecular weight of a substance, you can determine the mass of one mole of that substance. Therefore, the correct answer is "One mole has a mass numerically equal to the molecular weight of the substance."Rate this question:
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- 43.
Which processes do the Rankine cycle contain?
- A.
Two isothermal and two isochoric processes
- B.
Two isentropic and two isobaric processes
- C.
Two isentropic and two isothermal processes
- D.
Two isothermal and two isobaric processes
Correct Answer
B. Two isentropic and two isobaric processesExplanation
The Rankine cycle is a thermodynamic cycle used in power plants to convert heat into mechanical work. It consists of four processes: two isentropic processes (adiabatic and reversible) and two isobaric processes (constant pressure). The isentropic processes involve the compression and expansion of the working fluid, while the isobaric processes involve the heating and cooling of the fluid at constant pressure. This combination of processes allows for efficient energy conversion in power generation systems.Rate this question:
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- 44.
With increasing temperature of Intake Air, IC engine efficiency
- A.
Decreases
- B.
Increases
- C.
Remains Same
- D.
Depends On Other Factors
Correct Answer
A. DecreasesExplanation
As the temperature of the intake air increases, the efficiency of an internal combustion (IC) engine decreases. This is because hotter air has a lower density, which means there is less oxygen available for combustion. This leads to incomplete combustion and a decrease in engine efficiency. Additionally, higher intake air temperatures can also cause increased heat loss and increased risk of engine knocking, further reducing efficiency. Therefore, increasing the temperature of intake air has a negative impact on the efficiency of an IC engine.Rate this question:
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- 45.
A house refrigerator with its door open is switched on in a closed room. The air in the room is
- A.
Cooled
- B.
Remains at same temperature
- C.
Heated
- D.
Heated or cooled depending on atmospheric pressure
Correct Answer
C. HeatedExplanation
When a house refrigerator with its door open is switched on in a closed room, the air in the room will be heated. This is because the refrigerator works by removing heat from the inside and releasing it to the outside. When the door is open, the heat from the condenser coils at the back of the refrigerator will be released into the room, causing the temperature of the air in the room to increase. Therefore, the air in the room will be heated.Rate this question:
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- 46.
A 10 kg mass is hung from 2 light, inextensible strings as shown. The tension in the horizontal string is nearly
- A.
49 N
- B.
57 N
- C.
100 N
- D.
0 N
Correct Answer
B. 57 NExplanation
The tension in the horizontal string is nearly 57 N because the weight of the 10 kg mass is evenly distributed between the two strings. Each string will therefore support half of the weight, which is 5 kg or 49 N. However, since the strings are at an angle, there will be a component of the tension in the horizontal direction. By using trigonometry, it can be determined that this component is equal to the tension in the horizontal string, which is approximately 57 N.Rate this question:
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- 47.
A block of ice at -10 °C is slowly heated and converted to steam at 100 °C. Which of the following curves represent the phenomena qualitatively?
- A.
Option 1
- B.
Option 2
- C.
Option 3
- D.
Option 4
Correct Answer
A. Option 1Explanation
Option 1 represents the phenomena qualitatively because it shows a gradual increase in temperature as the ice block is heated, followed by a plateau at 0 °C when the ice starts melting. After that, the temperature continues to rise until it reaches 100 °C, where it remains constant during the phase change from liquid to gas. This is consistent with the process of heating ice and converting it to steam.Rate this question:
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- 48.
A engine works on Carnot cycle between 727 °C and 227 °C. The efficiency of the engine is
- A.
50%
- B.
75.4%
- C.
31.2%
- D.
68.8%
Correct Answer
A. 50%Explanation
The efficiency of a Carnot cycle engine is given by (T1 - T2) / T1, where T1 is the temperature of the hot reservoir and T2 is the temperature of the cold reservoir. In this case, the temperature of the hot reservoir is 727 °C and the temperature of the cold reservoir is 227 °C. Plugging these values into the formula, we get (727 - 227) / 727 = 500 / 727 ≈ 0.688, which is approximately 68.8%. Therefore, the correct answer is 68.8%.Rate this question:
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- 49.
An elevator has a mass of 5000 kg. When the tension in the supporting cable is 60 kN, the acceleration of the elevator is nearly
- A.
8 m/s2
- B.
12 m/s 2
- C.
-2 m/s2
- D.
2 m/s2
Correct Answer
D. 2 m/s2Explanation
The acceleration of the elevator can be determined using Newton's second law, which states that the acceleration is equal to the net force divided by the mass of the object. In this case, the net force acting on the elevator is the tension in the supporting cable, which is 60 kN. Converting this to Newtons, we get 60,000 N. Dividing this by the mass of the elevator, which is 5000 kg, we get an acceleration of 12 m/s^2. Therefore, the correct answer is 12 m/s^2.Rate this question:
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- 50.
Misrun is a casting defect which occurs due to
- A.
Very high pouring temperature of metal
- B.
Absorption of gases by liquid metal
- C.
Insufficient fluidity of molten metal
- D.
Improper alignment of mould flasks
Correct Answer
C. Insufficient fluidity of molten metalExplanation
Misrun is a casting defect that occurs when the molten metal does not flow properly and completely fill the mold cavity. This lack of fluidity can be caused by various factors such as high viscosity of the molten metal, inadequate pouring temperature, or improper alloy composition. When the molten metal does not have enough fluidity, it fails to reach all parts of the mold, resulting in incomplete castings with missing sections or voids. Therefore, the correct answer is "Insufficient fluidity of molten metal."Rate this question:
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