Question 1 of 18

1. 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 1 of 18

Question 2 of 18

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

Defective pony motor

Insufficient excitation

Short in damper winding

Open in damper winding

Question 2 of 18

Question 3 of 18

3. What is the name of the converter?

Silicon controlled rectifier

Rotary converter

Mercury arc rectifier

Metal rectifier

Question 3 of 18

Question 4 of 18

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

Maintain constant speed

Excite the field winding

Start the synchronous motor

Maintain power factor

Question 4 of 18

Question 5 of 18

5. What is the advantage of motor generator set?

DC output voltage can be easily controlled

High efficiency

Noiseless

Low maintenance required

Question 5 of 18

Question 6 of 18

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

Produce high current to start rotate the motor

Produces torque and runs near in synchronous speed

Produce a high magnetic-field to maintain a constant speed

Produce high voltage to initiate the rotation

Question 6 of 18

Question 7 of 18

7. Which application requires only DC?

Electroplating

Stepping up of voltage

Operating induction motor

Operating repulsion motor

Question 7 of 18

Question 8 of 18

8. Which is the main application of synchronous motor?

Paper rolling mills

Elevators

Power factor correction device

AC to DC converter

Question 8 of 18

Question 9 of 18

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

Increasing the speed of motor

Varying the line voltage

Varying the field excitation

Decreasing the speed of motor

Question 9 of 18

Question 10 of 18

10. Which converter is having high efficiency?

SCR converter

Motor generator set

Rotary converter

Mercury arc rectifier

Question 10 of 18

Question 11 of 18

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

Reduces voltage drop

Converts AC to DC

Helps to deliver without noise

Collects the delivered direct current

Question 11 of 18

Question 12 of 18

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

Very sensitive to temperature

Heavily doped device

Designed for light emitting

Very low power device

Question 12 of 18

Question 13 of 18

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

Start the motor initially

Reduce the losses

Run the motor with over load

Run the motor at synchronous speed

Question 13 of 18

Question 14 of 18

14. Which converting device can be over loaded?

Rotary converter

Rectifier unit

Motor generator set

Mercury arc rectifier

Question 14 of 18

Question 15 of 18

15. What is the function of inverter?

Convert A.C to D.C

Convert D.C to A.C

Smoothening A.C sine wave

Convert pulsating DC into pure D.C

Question 15 of 18

Question 16 of 18

16. What is the name of the converter?

Motor-Generator set

Mercury arc rectifier

Rotary converter

Metal rectifier

Question 16 of 18

Question 17 of 18

17. Which acts as both inverter and converter?

Mercury arc rectifier

Synchronous converter

Semi conductor diode

Metal rectifier

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 motor load

Varying the rotor excitation

Varying stator current in motor

Question 18 of 18