ELECTRICIAN 2nd YEAR MODULE – Synchronous Motor and MG Set ONLINE TEST

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. Which converter is having high efficiency?

Rotary converter

SCR converter

Motor generator set

Mercury arc rectifier

Question 2 of 18

Question 3 of 18

3. Which acts as both inverter and converter?

Synchronous converter

Mercury arc rectifier

Semi conductor diode

Metal rectifier

Question 3 of 18

Question 4 of 18

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

Insufficient excitation

Open in damper winding

Defective pony motor

Short in damper winding

Question 4 of 18

Question 5 of 18

5. What is the advantage of motor generator set?

Low maintenance required

High efficiency

Noiseless

DC output voltage can be easily controlled

Question 5 of 18

Question 6 of 18

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

Helps to deliver without noise

Converts AC to DC

Collects the delivered direct current

Reduces voltage drop

Question 6 of 18

Question 7 of 18

7. 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 7 of 18

Question 8 of 18

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

Reduce the losses in motor

Carry more load in motor

Improve the power factor

Run the motor at synchronous speed

Question 8 of 18

Question 9 of 18

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

Run the motor at synchronous speed

Reduce the losses

Run the motor with over load

Start the motor initially

Question 9 of 18

Question 10 of 18

10. What is the name of the converter?

Silicon controlled rectifier

Metal rectifier

Mercury arc rectifier

Rotary converter

Question 10 of 18

Question 11 of 18

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

Varying stator current in motor

Varying the motor load

Varying the rotor excitation

Varying stator voltage in motor

Question 11 of 18

Question 12 of 18

12. Which is the main application of synchronous motor?

Power factor correction device

AC to DC converter

Elevators

Paper rolling mills

Question 12 of 18

Question 13 of 18

13. Which application requires only DC?

Operating repulsion motor

Stepping up of voltage

Operating induction motor

Electroplating

Question 13 of 18

Question 14 of 18

14. What is the name of the converter?

Metal rectifier

Rotary converter

Motor-Generator set

Mercury arc rectifier

Question 14 of 18

Question 15 of 18

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

Produce high voltage to initiate the rotation

Produces torque and runs near in synchronous speed

Produce high current to start rotate the motor

Produce a high magnetic-field to maintain a constant speed

Question 15 of 18

Question 16 of 18

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

Very sensitive to temperature

Very low power device

Designed for light emitting

Heavily doped device

Question 16 of 18

Question 17 of 18

17. Which converting device can be over loaded?

Mercury arc rectifier

Motor generator set

Rotary converter

Rectifier unit

Question 17 of 18

Question 18 of 18

18. What is the function of inverter?

Convert A.C to D.C

Smoothening A.C sine wave

Convert D.C to A.C

Convert pulsating DC into pure D.C

Question 18 of 18