1.
The series and parallel resonance on L-C circuit' differs in that
Correct Answer
A.
Series resistance needs a low-resistance source for sharp rise in current
Explanation
In a series resonance on an L-C circuit, the current reaches its maximum value when the impedance is at its minimum. This occurs when the inductive reactance and the capacitive reactance cancel each other out. To achieve a sharp rise in current, the series resistance needs to be low in order to minimize the overall impedance of the circuit. This allows the current to flow easily without being hindered by high resistance.
2.
Which one correct ?
Correct Answer
C. Option c
3.
In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters?
Correct Answer
A.
220 V
Explanation
The voltmeters in each of the three coils of a three-phase generator will indicate the same voltage as the alternating voltage induced in the coils. Since the alternating voltage has an r.m.s. value of 220 V, the voltmeters will also indicate 220 V.
4.
In a highly capacitive circuit the
Correct Answer
C.
Reactive power is more than the actual power
Explanation
In a highly capacitive circuit, the reactive power is more than the actual power. This is because in a capacitive circuit, the current leads the voltage, causing the power factor to be lagging. As a result, the reactive power, which represents the energy stored and released by the capacitor, is greater than the actual power, which is the real power consumed by the circuit.
5.
The power factor at resonance in R-L-C parallel circuit is
Correct Answer
D.
Unity
Explanation
At resonance in an R-L-C parallel circuit, the reactive components cancel each other out, leaving only the resistive component. This means that the circuit behaves purely resistive, and the power factor is therefore unity.
6.
The hot resistance of the bulb's filament is higher than its cold resistance because the temperature coefficient of the filament is
Correct Answer
C.
Positive
Explanation
The hot resistance of the bulb's filament is higher than its cold resistance because the temperature coefficient of the filament is positive. This means that as the temperature of the filament increases, its resistance also increases. Therefore, when the bulb is turned on and the filament heats up, its resistance increases, resulting in a higher hot resistance compared to its cold resistance.
7.
Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be
Correct Answer
D.
10 ohms
Explanation
The resistance of a conductor is directly proportional to its length and inversely proportional to its cross-sectional area. In this case, the conductor with the smaller cross-sectional area has a resistance of 40 ohms. Since the cross-sectional area is four times smaller, the resistance of the other conductor will be four times larger. Therefore, the resistance of the other conductor will be 4 * 40 ohms, which is equal to 160 ohms.
8.
Which of the following statement is correct?
Correct Answer
A.
A semiconductor is a material whose conductivity is same as between that of a conductor and an insulator
Explanation
Semiconductors are materials that have conductivity levels between those of conductors and insulators. Conductors have high conductivity, allowing electric current to flow easily, while insulators have low conductivity, preventing the flow of electric current. Semiconductors fall in between, with a moderate level of conductivity. This makes semiconductors useful in various electronic devices, as their conductivity can be controlled and manipulated.
9.
The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 Ω load. The turns ratio is 3:1. What is the secondary voltage?
Correct Answer
B.
20 V
Explanation
The turns ratio of 3:1 means that for every 3 turns in the primary coil, there is 1 turn in the secondary coil. Since the primary coil is connected to a 60 V ac source, the voltage across the secondary coil can be calculated using the turns ratio.
Voltage across secondary coil = (Voltage across primary coil) * (Number of turns in secondary coil / Number of turns in primary coil)
= 60 V * (1/3)
= 20 V
Therefore, the secondary voltage is 20 V.
10.
In a certain transformer, the input power to the primary is 120 W. If 8.5 W are lost to the winding resistance, what is the output power to the load, neglecting any other issues?
Correct Answer
C.
111.5 W
Explanation
The input power to the primary is 120 W and 8.5 W are lost to the winding resistance. This means that the total power delivered to the load is 120 W - 8.5 W = 111.5 W. Neglecting any other issues, the output power to the load is therefore 111.5 W.
11.
A 3-phase 4-wire system is commonly used on
Correct Answer
D.
Secondary distribution
Explanation
A 3-phase 4-wire system is commonly used on secondary distribution. This is because the secondary distribution refers to the delivery of electricity from a distribution transformer to individual customers. A 3-phase 4-wire system is ideal for this purpose as it provides a balanced and efficient distribution of power, allowing for greater reliability and capacity. Additionally, the 4-wire system allows for the inclusion of a neutral wire, which is necessary for the safe and effective distribution of electricity to residential and commercial buildings.
12.
A booster is a
Correct Answer
A.
Series wound generator
Explanation
A booster is a series wound generator because a series wound generator is a type of generator where the field winding is connected in series with the armature winding. In this configuration, the current flows through both the field winding and the armature winding, creating a strong magnetic field that generates electricity. This type of generator is commonly used in applications where a high starting torque is required, such as in electric vehicles or industrial machinery.
13.
A thermistor is a type of
Correct Answer
B.
Resistor
Explanation
A thermistor is a type of resistor that is designed to change its resistance in response to changes in temperature. It is often used in temperature sensing applications, where its resistance can be measured to determine the temperature of the surrounding environment.
14.
For handling greater currents induction watt-meters are used in conjunction with
Correct Answer
B.
Current transformers
Explanation
Induction watt-meters are used to measure power in high current circuits. However, these watt-meters cannot handle high currents directly. Therefore, they are used in conjunction with current transformers, which step down the high current to a level that can be measured by the watt-meter. This allows for accurate power measurement in circuits with greater currents.
15.
Coefficient of friction depends upon
Correct Answer
B. Nature of surface only
Explanation
The coefficient of friction is a measure of the amount of friction between two surfaces. It depends on the nature of the surfaces in contact, such as their roughness, smoothness, and the materials they are made of. The area of contact does not affect the coefficient of friction. Therefore, the correct answer is "Nature of surface only."
16.
Which of the following is a vector quantity?
Correct Answer
C.
Momentum
Explanation
Momentum is a vector quantity because it has both magnitude and direction. It is defined as the product of an object's mass and its velocity, and its direction is the same as the direction of the object's velocity. In contrast, energy, mass, and angle are scalar quantities, which only have magnitude and no direction.
17.
The maximum velocity of a particle moving with simple harmonic motion is
Correct Answer
B.
ωr
Explanation
The maximum velocity of a particle in simple harmonic motion is given by the product of the angular frequency (ω) and the amplitude (r) of the motion. This is because the velocity of the particle is directly proportional to the amplitude of the motion and the angular frequency determines the rate at which the particle oscillates. Therefore, the correct answer is ωr.
18.
The moment of a force
Correct Answer
D.
All of the above
Explanation
The correct answer is "All of the above" because all three statements provide accurate explanations of the moment of a force. The first statement defines the moment of a force as the turning effect produced by a force on the body. The second statement states that the moment is equal to the product of the force and the perpendicular distance between a point and the line of action of the force. The third statement relates the moment to the area of a triangle formed by the line representing the force and the point about which the moment is taken. Therefore, all three statements are correct explanations of the moment of a force.
19.
A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
Correct Answer
B.
Parabola
Explanation
When a heavy string is attached at two ends at the same horizontal level and the central dip is very small, the resulting curve formed is a parabola. This is because the shape formed by a heavy string under its own weight is influenced by gravity, causing it to form a curve. The curve that is formed in this scenario is a parabola, which is a U-shaped curve.
20.
The mechanical advantage of a lifting machine is the ratio of
Correct Answer
B.
Load lifted to the effort applied
Explanation
The mechanical advantage of a lifting machine is determined by the ratio of the load lifted to the effort applied. This means that the mechanical advantage indicates how much easier it is to lift a load using the machine compared to lifting it directly by applying the effort alone. The larger the ratio, the greater the mechanical advantage and the easier it is to lift the load.
21.
From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the centre of circular plate
Correct Answer
A.
0.5 cm
Explanation
The radius of the circular plate is 3 cm (half of the diameter). The diameter of the circle cut out is also 3 cm (since it is a radius of the plate). The distance from the center of the plate to the edge of the cut out circle is the remaining radius of the plate, which is 3 cm - 2.5 cm = 0.5 cm. Therefore, the answer is 0.5 cm.
22.
Which of the following is not the unit of energy?
Correct Answer
C.
Watt
Explanation
The unit of energy is not watt. Watt is the unit of power, which is the rate at which energy is transferred or converted. Energy can be measured in units such as kilogram meter (kg m), kilocalorie (kcal), or watt-hour (Watt hours).
23.
The range of projectile will be maximum for a given velocity of projectile, when the angle of projection (α) is
Correct Answer
C.
45° + β/2
Explanation
The range of a projectile is the maximum horizontal distance it can travel. To maximize the range, the projectile needs to be launched at an angle that balances the vertical and horizontal components of its velocity. This angle is 45 degrees. Adding β/2 to this angle will not change the fact that 45 degrees is the optimal angle for maximum range. Therefore, the correct answer is 45° + β/2.
24.
The power developed by a body acted upon by a torque 'T' Newton meter (N - m) and revolving at ω radian/s is given by
Correct Answer
A.
T.ω (in watts)
Explanation
The power developed by a body acted upon by a torque 'T' Newton meter (N - m) and revolving at ω radian/s is given by T.ω (in watts). This formula calculates the power in watts based on the torque and angular velocity of the body.
25.
Which one do you like?
Correct Answer
C.
(h/3) [(2a + b)/(a + b)]
Explanation
The correct answer is (h/3) [(2a + b)/(a + b)].
26.
In the equation of virtual work, following force is neglected
Correct Answer
D.
All of the above
Explanation
The equation of virtual work is used to calculate the work done by a system of forces. In this equation, the reaction of any smooth surface with which the body is in contact is neglected. This is because the smooth surface does not provide any resistance or force that needs to be considered in the calculation. Similarly, the reaction of a rough surface of a body which rolls on it without slipping is also neglected because the rough surface does not affect the work done by the system of forces. Additionally, the reaction at a point or an axis, fixed in space, around which a body is constrained to turn is also neglected in the equation of virtual work. Therefore, all of the above reactions are neglected in the equation.
27.
If rain is falling in the opposite direction of the movement of a pedestrian, he has to hold his umbrella
Correct Answer
D.
Less inclined when standing
Explanation
When rain is falling in the opposite direction of the movement of a pedestrian, he has to hold his umbrella less inclined when standing. This is because when the pedestrian is standing still, the umbrella needs to be held at a higher angle to provide maximum coverage and protect the pedestrian from getting wet. However, when the pedestrian is moving, the forward motion helps to create a natural shield against the rain, allowing the umbrella to be held at a lower angle and still provide adequate protection.
28.
The loss of kinetic energy during inelastic impact, is given by (where m_{1} = Mass of the first body,m_{2} = Mass of the second body, and u_{1} and u_{2} = Velocities of the first and second bodies respectively.)
Correct Answer
A.
[m₁ m₂/2(m₁ + m₂)] (u₁ - u₂)²
Explanation
The correct answer is [m₁ m₂/2(m₁ + m₂)] (u₁ - u₂)². This formula represents the loss of kinetic energy during an inelastic impact. It takes into account the masses of both bodies (m₁ and m₂) and the velocities of the bodies before the impact (u₁ and u₂). The formula calculates the difference in velocities (u₁ - u₂), squares it, and multiplies it by the product of the masses divided by twice the sum of the masses. This equation accurately represents the loss of kinetic energy in an inelastic collision.
29.
If a suspended body is struck at the center of percussion, then the pressure on die axis passing through the point of suspension will be
Correct Answer
C.
Zero
Explanation
When a suspended body is struck at the center of percussion, the pressure on the axis passing through the point of suspension will be zero. This is because the center of percussion is the point on the body where the impact force produces no reaction force at the point of suspension. As a result, there is no pressure exerted on the axis passing through the point of suspension.
30.
A cube subjected to three mutually perpendicular stress of equal intensity p expenses a volumetric strain
Correct Answer
C.
3p/ E × (1 - 2/m)
Explanation
Answer: Option C
Solution: Stress p in x-direction causes tensile strain p/E in x-direction, while the ‘p’ in ‘y’ and ‘z’ direction causes compressive strains µ(p/E) in x-direction.
Therefore, ex = p/E - µ(p/E) - µ(p/E) = p/E × (1- 2µ)
So, ey =p/E × (1- 2µ), ez = p/E × (1- 2µ)
Therefore, Volumetric Strain, ev = ex + ey + ez = 3p/E × (1- 2µ) = 3p/E × (1 – 2/m)
31.
The strain energy stored in a solid circular shaft subjected to shear stress (τ), is:
(Where, G = Modulus of rigidity for the shaft material)
Correct Answer
A.
τ²/ 2G × Volume of shaft
Explanation
The correct answer is τ²/ 2G × Volume of shaft. This is because the strain energy stored in a solid circular shaft subjected to shear stress is directly proportional to the square of the shear stress (τ) and the volume of the shaft. The constant of proportionality is 2 times the modulus of rigidity (G) for the shaft material.
32.
The stress induced in a body, when suddenly loaded, is _________ the stress induced when the same load is applied gradually.
Correct Answer
C.
Twice
Explanation
When a body is suddenly loaded, the stress induced in the body is twice the stress induced when the same load is applied gradually. This is because sudden loading causes a rapid increase in the force applied to the body, leading to a higher stress compared to gradual loading where the force is applied slowly over time.
33.
The torque transmitted by a solid shaft of diameter (D) is (where τ = Maximum allowable shear stress)
Correct Answer
B.
π /16 × τ × D³
Explanation
The correct answer is π/16 × τ × D³ because it is the correct formula for calculating the torque transmitted by a solid shaft of diameter D. The formula involves multiplying the maximum allowable shear stress (τ) by the diameter cubed (D³) and then multiplying that by π/16. This formula is derived from the principles of solid mechanics and is used to determine the maximum torque that a solid shaft can transmit without exceeding the allowable shear stress.
34.
If the slenderness ratio for a column is 100, then it is said to be a _________ column.
Correct Answer
A.
Long
Explanation
If the slenderness ratio for a column is 100, it is said to be a long column. The slenderness ratio is the ratio of the effective length of the column to its least radius of gyration. A high slenderness ratio indicates that the column is long and slender, which means it is more prone to buckling under compressive loads. Therefore, a slenderness ratio of 100 indicates a long column.
35.
A body is subjected to a tensile stress of 1200 MPa on one plane and another tensile stress of 600 MPa on a plane at right angles to the former. It is also subjected to a shear stress of 400 MPa on the same planes. The maximum normal stress will be
Correct Answer
D.
1400 MPa
Explanation
Answer: Option D
Solution: tan2θ = 2q/ (p x - p y) = (2 × 400)/ (1200 – 600) = 1.33
Therefore, 2θ = tan⁻¹ 1.33 = 53.06°
Therefore, pn = 1200 + 600)/ 2 + (1200 – 600)/ 2 × cos 53.06 + 400 sin 530.6
=900 + 180.294 + 319.70
=1400 MPa.
Note:- Normal stress component, (pn ) on a plane:- pn = (p x + p y)/2 + (p x - p y)/2 × cos2θ + q sin2θ
Tangential Stress component, (pt) ¬ on a plane: - pt = (p x - p y)/2 × sin2θ – q cos2θ
Inclination θ between p x and p y is tan 2θ = 2q / (p x - p y)
36.
Young’s modulus of a wire is defined as the stress which will increase the length of wire compared to its original length by
Correct Answer
B.
Same amount
Explanation
Young's modulus is a measure of the stiffness of a material. It is defined as the ratio of stress to strain. In the case of a wire, Young's modulus is the stress required to increase the length of the wire by the same amount compared to its original length. Therefore, the correct answer is "Same amount" because Young's modulus measures the amount of deformation in the wire.
37.
True stress strain-curve for materials is plotted between
Correct Answer
B.
Load/ instantaneous cross-sectional area and log_{e} (original area/ instantaneous area)
Explanation
The correct answer is Load/ instantaneous cross-sectional area and loge (original area/ instantaneous area) because the true stress-strain curve for materials is plotted using the load divided by the instantaneous cross-sectional area, which represents the true stress, and the natural logarithm of the ratio of the original area to the instantaneous area, which represents the true strain. This relationship accounts for the change in area as the material undergoes deformation and provides a more accurate representation of the material's behavior under stress.
38.
The force acting along the circumference will cause stress in the walls in a direction normal to the longitudinal axis of cylinder; This stress is called
Correct Answer
B.
Hoop stress
Explanation
The force acting along the circumference of the cylinder will cause stress in the walls in a direction normal to the longitudinal axis. This stress is known as hoop stress, which is the stress experienced by the walls of a cylindrical object due to the internal or external pressure. Hoop stress is important in determining the strength and stability of cylindrical structures such as pipes and pressure vessels.
39.
The hoop stress in a riveted cylindrical shell of diameter (d), thickness (t) and subjected to an internal pressure (p) is (where η = Efficiency of the riveted joint)
Correct Answer
B.
pd/η × 2t
Explanation
The hoop stress in a riveted cylindrical shell is given by the formula pd/η × 2t. This formula takes into account the internal pressure (p), diameter (d), and thickness (t) of the shell, as well as the efficiency of the riveted joint (η). The factor of 2t in the formula accounts for the double thickness of the shell in the hoop direction.
40.
The bending moment at the free end of a cantilever beam is
Correct Answer
A.
Zero
Explanation
At the free end of a cantilever beam, there is no support or constraint, which means there are no external forces or moments acting on the beam. As a result, there is no bending moment at the free end of the beam. Therefore, the correct answer is zero.
41.
What do we call a network whose elements may be separated by some distance? It usually involves two or more small networks and dedicated high-speed telephone lines.
Correct Answer
C.
WAN (Wide Area Network)
Explanation
A network whose elements may be separated by some distance and involves two or more small networks and dedicated high-speed telephone lines is called a Wide Area Network (WAN). A WAN is designed to connect computers and other devices across a large geographic area, such as different offices or cities. It allows for the transmission of data over long distances and provides a means for communication between the connected networks.
42.
What does SSL stand for?
Correct Answer
A.
Secure Socket Layer
Explanation
SSL stands for Secure Socket Layer. It is a protocol that provides secure communication over the internet. It ensures that the data transmitted between a web server and a browser remains encrypted and protected from unauthorized access. SSL uses encryption algorithms to scramble the data, making it unreadable to anyone who intercepts it. This helps to prevent sensitive information such as credit card numbers, passwords, and personal data from being stolen or tampered with during transmission. SSL is widely used for secure online transactions, such as e-commerce websites, online banking, and email services.
43.
The IBM PC-XT was the first to include a hard drive. What was the capacity of this disk?
Correct Answer
C.
10 MB
Explanation
The IBM PC-XT was the first computer to include a hard drive, and the capacity of this disk was 10 MB.
44.
The arranging of data in a logical sequence is called:
Correct Answer
A. sorting
Explanation
The process of arranging data in a logical sequence is referred to as sorting. This involves organizing the data in a specific order, such as ascending or descending, based on certain criteria. Sorting allows for easier retrieval and analysis of the data, making it more manageable and understandable. Classifying refers to categorizing or grouping data based on similarities or characteristics. Reproducing refers to creating copies or duplicating data. Summarizing involves condensing or summarizing the data to provide a concise overview.
45.
Which protocol provides e-mail facility among different hosts?
Correct Answer
B. SMTP
Explanation
SMTP (Simple Mail Transfer Protocol) is the correct answer because it is the protocol specifically designed for sending and receiving emails between different hosts. FTP (File Transfer Protocol) is used for transferring files, TELNET is used for remote login and control of other computers, and SNMP (Simple Network Management Protocol) is used for managing and monitoring network devices. Therefore, SMTP is the most appropriate protocol for providing email facility among different hosts.
46.
EBCDIC can code up to how many different charracters?
Correct Answer
A. 256
Explanation
EBCDIC (Extended Binary Coded Decimal Interchange Code) is a character encoding used in mainframe computers. It can code up to 256 different characters. This is because EBCDIC uses an 8-bit binary code, allowing for a total of 256 possible combinations. Each combination represents a different character or symbol that can be encoded using EBCDIC. Therefore, the correct answer is 256.
47.
GUI stands for
Correct Answer
C. GrapHical User Interface
Explanation
GUI stands for Graphical User Interface. It is a type of interface that allows users to interact with electronic devices through graphical elements such as icons, buttons, and menus. This interface is designed to be intuitive and user-friendly, making it easier for users to navigate and operate the device or software. The graphical elements provide a visual representation of the functions and options available, making it easier for users to understand and access them. GUIs are widely used in various electronic devices and software applications to enhance the user experience.
48.
Time during which a job is processed by the computer is:
Correct Answer
A. Execution Time
Explanation
The time during which a job is processed by the computer is referred to as execution time. This is the duration in which the computer performs the necessary tasks and operations required by the job. It includes the time taken for the CPU to execute the instructions, access and retrieve data from memory, and perform any other computations needed. Execution time is an important factor in measuring the efficiency and performance of a computer system.
49.
Which of the following circuit is used as a 'Memory device' in computers?
Correct Answer
B. Flip Flop
Explanation
A flip flop is a type of circuit that is commonly used as a memory device in computers. It is designed to store and hold a single bit of information, which can be either a logic 0 or a logic 1. Flip flops are used in computer memory systems to store data temporarily or permanently, depending on the type of flip flop used. They are crucial for the storage and retrieval of data in computer systems, making them an essential component in memory devices.
50.
Which of the following is not an advantage of magnetic disk storage?
Correct Answer
D. None of the above
Explanation
The given answer "None of the above" is correct because all of the options listed are advantages of magnetic disk storage. The access time of magnetic disk is indeed much less than that of magnetic tape, making it faster. Disk storage is also less expensive than tape storage, making it more cost-effective. Additionally, disk storage is longer lasting than magnetic tape, as tapes can degrade over time. Therefore, all of the options are advantages of magnetic disk storage.