Question 1 of 18

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

Excite the field winding

Maintain constant speed

Start the synchronous motor

Maintain power factor

Question 1 of 18

Question 2 of 18

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

Varying the rotor excitation

Varying the motor load

Varying stator current in motor

Varying stator voltage in motor

Question 2 of 18

Question 3 of 18

3. Which converter is having high efficiency?

Rotary converter

SCR converter

Motor generator set

Mercury arc rectifier

Question 3 of 18

Question 4 of 18

4. Which acts as both inverter and converter?

Synchronous converter

Semi conductor diode

Mercury arc rectifier

Metal rectifier

Question 4 of 18

Question 5 of 18

5. Which application requires only DC?

Stepping up of voltage

Operating repulsion motor

Operating induction motor

Electroplating

Question 5 of 18

Question 6 of 18

6. Which converting device can be over loaded?

Mercury arc rectifier

Rectifier unit

Motor generator set

Rotary converter

Question 6 of 18

Question 7 of 18

7. What is the advantage of motor generator set?

High efficiency

Noiseless

Low maintenance required

DC output voltage can be easily controlled

Question 7 of 18

Question 8 of 18

8. Which is the main application of synchronous motor?

AC to DC converter

Power factor correction device

Paper rolling mills

Elevators

Question 8 of 18

Question 9 of 18

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

Very low power device

Heavily doped device

Designed for light emitting

Very sensitive to temperature

Question 9 of 18

Question 10 of 18

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

Converts AC to DC

Reduces voltage drop

Helps to deliver without noise

Collects the delivered direct current

Question 10 of 18

Question 11 of 18

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

Produce high current to start rotate the motor

Produce high voltage to initiate the rotation

Produce a high magnetic-field to maintain a constant speed

Produces torque and runs near in synchronous speed

Question 11 of 18

Question 12 of 18

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

Increasing the speed of motor

Decreasing the speed of motor

Varying the line voltage

Varying the field excitation

Question 12 of 18

Question 13 of 18

13. 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 13 of 18

Question 14 of 18

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

Carry more load in motor

Improve the power factor

Run the motor at synchronous speed

Reduce the losses in motor

Question 14 of 18

Question 15 of 18

15. What is the name of the converter?

Mercury arc rectifier

Rotary converter

Metal rectifier

Silicon controlled rectifier

Question 15 of 18

Question 16 of 18

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

Run the motor with over load

Run the motor at synchronous speed

Start the motor initially

Reduce the losses

Question 16 of 18

Question 17 of 18

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

Defective pony motor

Open in damper winding

Insufficient excitation

Short in damper winding

Question 17 of 18

Question 18 of 18

18. What is the name of the converter?

Motor-Generator set

Mercury arc rectifier

Metal rectifier

Rotary converter

Question 18 of 18