Question 1 of 18

1. Which application requires only DC?

Operating induction motor

Stepping up of voltage

Operating repulsion motor

Electroplating

Question 1 of 18

Question 2 of 18

2. What is the function of damper windings in synchronous motor?

Maintain power factor

Maintain constant speed

Excite the field winding

Start the synchronous motor

Question 2 of 18

Question 3 of 18

3. What is the name of the converter?

Motor-Generator set

Mercury arc rectifier

Rotary converter

Metal rectifier

Question 3 of 18

Question 4 of 18

4. Why D.C supply is necessary for synchronous motor operation?

Run the motor with over load

Reduce the losses

Run the motor at synchronous speed

Start the motor initially

Question 4 of 18

Question 5 of 18

5. What is the name of the converter?

Mercury arc rectifier

Silicon controlled rectifier

Rotary converter

Metal rectifier

Question 5 of 18

Question 6 of 18

6. Which is the main application of synchronous motor?

Power factor correction device

AC to DC converter

Paper rolling mills

Elevators

Question 6 of 18

Question 7 of 18

7. Which acts as both inverter and converter?

Synchronous converter

Semi conductor diode

Mercury arc rectifier

Metal rectifier

Question 7 of 18

Question 8 of 18

8. What is the advantage of motor generator set?

Noiseless

Low maintenance required

High efficiency

DC output voltage can be easily controlled

Question 8 of 18

Question 9 of 18

9. Which converter is having high efficiency?

Mercury arc rectifier

SCR converter

Motor generator set

Rotary converter

Question 9 of 18

Question 10 of 18

10. Why exciter is essential to run a synchronous motor?

Run the motor at synchronous speed

Improve the power factor

Reduce the losses in motor

Carry more load in motor

Question 10 of 18

Question 11 of 18

11. How synchronous motor works as a power factor corrector?

Decreasing the speed of motor

Increasing the speed of motor

Varying the field excitation

Varying the line voltage

Question 11 of 18

Question 12 of 18

12. Why the synchronous motor fails to run at synchronous speed?

Insufficient excitation

Open in damper winding

Defective pony motor

Short in damper winding

Question 12 of 18

Question 13 of 18

13. What is the function of inverter?

Convert D.C to A.C

Convert A.C to D.C

Smoothening A.C sine wave

Convert pulsating DC into pure D.C

Question 13 of 18

Question 14 of 18

14. What is the purpose of damper winding in a synchronous motor at starting?

Produces torque and runs near in synchronous speed

Produce high voltage to initiate the rotation

Produce high current to start rotate the motor

Produce a high magnetic-field to maintain a constant speed

Question 14 of 18

Question 15 of 18

15. Which converting device can be over loaded?

Rotary converter

Motor generator set

Mercury arc rectifier

Rectifier unit

Question 15 of 18

Question 16 of 18

16. Why the LED's are avoided as converters in rectifier diodes?

Very low power device

Designed for light emitting

Very sensitive to temperature

Heavily doped device

Question 16 of 18

Question 17 of 18

17. What is the function of the part marked as 'X' of the rotary converter?

Reduces voltage drop

Collects the delivered direct current

Helps to deliver without noise

Converts AC to DC

Question 17 of 18

Question 18 of 18

18. How the synchronous motor is used as a synchronous condenser?

Varying stator voltage in motor

Varying the rotor excitation

Varying stator current in motor

Varying the motor load

Question 18 of 18