11. Full form of PMMC is ____________
A. Permanent Magnet Moving Coil
B. Premature Magnet Moving Coil
C. Permanent Magnet Motion Coil
D. Peterson Magnet Motion Coil
Answer: A
The full form of PMMC is Permanent Magnet Moving Coil. It measures the average value of the applied input signal.
12. Fuel used in the train is ___________
A. Diesel
B. Kerosene
C. Petrol
D. Ice
Answer: A
The fuel used in the train is Diesel. Diesel fuel in trains provides more efficiency and more economy. It is more economical than air travel.
13. How much fuel does a train use per Km?
A. 7.85 L/Km
B. 7.97 L/Km
C. 6.59 L/Km
D. 7.15 L/Km
Answer: B
The average fuel consumed by a train is 7.97 L/Km. Consumption is the same for passenger and cargo trains.
14. Which motor is used in the electric train?
A. DC shunt motor
B. DC series motor
C. Synchronous motor
D. Stepper motor
Answer: B
DC series motor is used in electric trains. They provide a high starting torque. DC series motor is a universal motor that can run on DC as well as on AC.
15. Calculate the minimum time period for ASCI using the data: R=1 kΩ, C=1 μF.
A. 4 msec
B. 8 msec
C. 5 msec
D. 3 msec
Answer: A
The minimum time period for ASCI is a
4×R×C = 4×1×1×.001 = 4 msec.
The total time is the sum of charging and discharging time.
16. There are four types of friction.
A. True
B. False
Answer: B
There are two types of friction. Internal and external friction are types of friction. The coefficient of friction is independent of the force of friction.
17. Calculate the value of the coefficient of friction using the data: F=24 N, Normal force=12 N.
A. 2
B. 4
C. 8
D. 9
Answer: A
The coefficient of friction is the ratio of the friction force and normal force. It is dependent on the smoothness of the surface area.
μ=24÷12=2.
18. If the friction force value is doubled, calculate the new value of the coefficient of friction.
A. 4 times the original value
B. 2 times the original value
C. 7 times the original value
D. Remains the same
Answer: D
The value of the coefficient of friction will not change if the friction force is doubled. It only depends upon the nature of the surface.
19. The frictional force always acts in the _________ direction of motion of the body.
A. Opposite
B. Same
C. Perpendicular
D. Vertical
Answer: A
The friction of force always acts in the opposite direction of the motion of the body. It is a non-conservative force. It helps in the motion of the body.
20. Calculate the coefficient of friction if the angle of inclination is 60°.
A. 2.73
B. 1.73
C. 2.48
D. 1.41
Answer: B
The coefficient of friction is the tangent of the angle of the inclined plane. The value of μ is the tan(60°)=1.73. The coefficient of friction depends on the nature of the surface.
