Question 1 of 18

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

Reduce the losses in motor

Carry more load in motor

Run the motor at synchronous speed

Improve the power factor

Question 1 of 18

Question 2 of 18

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

Short in damper winding

Defective pony motor

Insufficient excitation

Open in damper winding

Question 2 of 18

Question 3 of 18

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

Very sensitive to temperature

Designed for light emitting

Heavily doped device

Very low power device

Question 3 of 18

Question 4 of 18

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

Converts AC to DC

Collects the delivered direct current

Reduces voltage drop

Helps to deliver without noise

Question 4 of 18

Question 5 of 18

5. Which application requires only DC?

Operating repulsion motor

Electroplating

Operating induction motor

Stepping up of voltage

Question 5 of 18

Question 6 of 18

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

Excite the field winding

Maintain power factor

Start the synchronous motor

Maintain constant speed

Question 6 of 18

Question 7 of 18

7. Which is the main application of synchronous motor?

Elevators

Paper rolling mills

AC to DC converter

Power factor correction device

Question 7 of 18

Question 8 of 18

8. What is the advantage of motor generator set?

Noiseless

Low maintenance required

DC output voltage can be easily controlled

High efficiency

Question 8 of 18

Question 9 of 18

9. Which acts as both inverter and converter?

Metal rectifier

Semi conductor diode

Synchronous converter

Mercury arc rectifier

Question 9 of 18

Question 10 of 18

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

Start the motor initially

Run the motor at synchronous speed

Reduce the losses

Run the motor with over load

Question 10 of 18

Question 11 of 18

11. Which converter is having high efficiency?

Mercury arc rectifier

SCR converter

Motor generator set

Rotary converter

Question 11 of 18

Question 12 of 18

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

Produces torque and runs near in synchronous speed

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

Question 12 of 18

Question 13 of 18

13. 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 13 of 18

Question 14 of 18

14. What is the name of the converter?

Motor-Generator set

Mercury arc rectifier

Metal rectifier

Rotary converter

Question 14 of 18

Question 15 of 18

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

Decreasing the speed of motor

Varying the line voltage

Increasing the speed of motor

Varying the field excitation

Question 15 of 18

Question 16 of 18

16. What is the name of the converter?

Mercury arc rectifier

Metal rectifier

Silicon controlled rectifier

Rotary converter

Question 16 of 18

Question 17 of 18

17. What is the function of inverter?

Convert D.C to A.C

Smoothening A.C sine wave

Convert A.C to D.C

Convert pulsating DC into pure D.C

Question 17 of 18

Question 18 of 18

18. Which converting device can be over loaded?

Rectifier unit

Motor generator set

Rotary converter

Mercury arc rectifier

Question 18 of 18