Question 1 of 18

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

Excite the field winding

Maintain power factor

Maintain constant speed

Start the synchronous motor

Question 1 of 18

Question 2 of 18

2. What is the function of inverter?

Convert A.C to D.C

Convert D.C to A.C

Convert pulsating DC into pure D.C

Smoothening A.C sine wave

Question 2 of 18

Question 3 of 18

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

Varying the motor load

Varying the rotor excitation

Varying stator voltage in motor

Varying stator current in motor

Question 3 of 18

Question 4 of 18

4. What is the advantage of motor generator set?

DC output voltage can be easily controlled

Low maintenance required

Noiseless

High efficiency

Question 4 of 18

Question 5 of 18

5. Which acts as both inverter and converter?

Semi conductor diode

Mercury arc rectifier

Synchronous converter

Metal rectifier

Question 5 of 18

Question 6 of 18

6. What is the name of the converter?

Metal rectifier

Motor-Generator set

Rotary converter

Mercury arc rectifier

Question 6 of 18

Question 7 of 18

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

Very sensitive to temperature

Heavily doped device

Very low power device

Designed for light emitting

Question 7 of 18

Question 8 of 18

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

Run the motor at synchronous speed

Reduce the losses in motor

Carry more load in motor

Improve the power factor

Question 8 of 18

Question 9 of 18

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

Collects the delivered direct current

Converts AC to DC

Reduces voltage drop

Helps to deliver without noise

Question 9 of 18

Question 10 of 18

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

Produce high voltage to initiate the rotation

Produce a high magnetic-field to maintain a constant speed

Produce high current to start rotate the motor

Produces torque and runs near in synchronous speed

Question 10 of 18

Question 11 of 18

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

Insufficient excitation

Defective pony motor

Short in damper winding

Open in damper winding

Question 11 of 18

Question 12 of 18

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

Increasing the speed of motor

Varying the field excitation

Decreasing the speed of motor

Varying the line voltage

Question 12 of 18

Question 13 of 18

13. What is the name of the converter?

Metal rectifier

Silicon controlled rectifier

Mercury arc rectifier

Rotary converter

Question 13 of 18

Question 14 of 18

14. Which converter is having high efficiency?

Motor generator set

Rotary converter

SCR converter

Mercury arc rectifier

Question 14 of 18

Question 15 of 18

15. Which is the main application of synchronous motor?

AC to DC converter

Power factor correction device

Paper rolling mills

Elevators

Question 15 of 18

Question 16 of 18

16. Which application requires only DC?

Electroplating

Stepping up of voltage

Operating repulsion motor

Operating induction motor

Question 16 of 18

Question 17 of 18

17. Which converting device can be over loaded?

Mercury arc rectifier

Rotary converter

Motor generator set

Rectifier unit

Question 17 of 18

Question 18 of 18

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

Run the motor at synchronous speed

Run the motor with over load

Start the motor initially

Reduce the losses

Question 18 of 18