Question 1 of 18

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

Run the motor at synchronous speed

Run the motor with over load

Reduce the losses

Start the motor initially

Question 1 of 18

Question 2 of 18

2. What is the function of inverter?

Convert pulsating DC into pure D.C

Convert D.C to A.C

Smoothening A.C sine wave

Convert A.C to D.C

Question 2 of 18

Question 3 of 18

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

Produce high current to start rotate the motor

Produce a high magnetic-field to maintain a constant speed

Produces torque and runs near in synchronous speed

Produce high voltage to initiate the rotation

Question 3 of 18

Question 4 of 18

4. 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 4 of 18

Question 5 of 18

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

Collects the delivered direct current

Reduces voltage drop

Converts AC to DC

Helps to deliver without noise

Question 5 of 18

Question 6 of 18

6. What is the advantage of motor generator set?

High efficiency

DC output voltage can be easily controlled

Low maintenance required

Noiseless

Question 6 of 18

Question 7 of 18

7. What is the name of the converter?

Rotary converter

Silicon controlled rectifier

Metal rectifier

Mercury arc rectifier

Question 7 of 18

Question 8 of 18

8. Which converting device can be over loaded?

Rotary converter

Mercury arc rectifier

Rectifier unit

Motor generator set

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 field excitation

Varying the line voltage

Decreasing the speed of motor

Question 9 of 18

Question 10 of 18

10. Which converter is having high efficiency?

SCR converter

Rotary converter

Mercury arc rectifier

Motor generator set

Question 10 of 18

Question 11 of 18

11. Which acts as both inverter and converter?

Synchronous converter

Semi conductor diode

Metal rectifier

Mercury arc rectifier

Question 11 of 18

Question 12 of 18

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

Varying the rotor excitation

Varying stator voltage in motor

Varying the motor load

Varying stator current in motor

Question 12 of 18

Question 13 of 18

13. Which is the main application of synchronous motor?

Power factor correction device

Elevators

Paper rolling mills

AC to DC converter

Question 13 of 18

Question 14 of 18

14. Which application requires only DC?

Stepping up of voltage

Operating repulsion motor

Electroplating

Operating induction motor

Question 14 of 18

Question 15 of 18

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

Open in damper winding

Short in damper winding

Defective pony motor

Insufficient excitation

Question 15 of 18

Question 16 of 18

16. What is the name of the converter?

Rotary converter

Mercury arc rectifier

Metal rectifier

Motor-Generator set

Question 16 of 18

Question 17 of 18

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

Start the synchronous motor

Maintain power factor

Excite the field winding

Maintain constant speed

Question 17 of 18

Question 18 of 18

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

Heavily doped device

Very low power device

Very sensitive to temperature

Designed for light emitting

Question 18 of 18