ELECTRICIAN 2nd YEAR MODULE – Synchronous Motor and MG Set

Question 1 of 18

1. Which converter is having high efficiency?

Mercury arc rectifier

Rotary converter

SCR converter

Motor generator set

Question 1 of 18

Question 2 of 18

2. What is the name of the converter?

Mercury arc rectifier

Silicon controlled rectifier

Rotary converter

Metal rectifier

Question 2 of 18

Question 3 of 18

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

Maintain power factor

Maintain constant speed

Excite the field winding

Start the synchronous motor

Question 3 of 18

Question 4 of 18

4. What is the name of the converter?

Mercury arc rectifier

Rotary converter

Motor-Generator set

Metal rectifier

Question 4 of 18

Question 5 of 18

5. What is the function of inverter?

Convert pulsating DC into pure D.C

Convert A.C to D.C

Convert D.C to A.C

Smoothening A.C sine wave

Question 5 of 18

Question 6 of 18

6. Which converting device can be over loaded?

Rotary converter

Motor generator set

Mercury arc rectifier

Rectifier unit

Question 6 of 18

Question 7 of 18

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

Carry more load in motor

Reduce the losses in motor

Run the motor at synchronous speed

Improve the power factor

Question 7 of 18

Question 8 of 18

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

Converts AC to DC

Collects the delivered direct current

Helps to deliver without noise

Reduces voltage drop

Question 8 of 18

Question 9 of 18

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

Very sensitive to temperature

Designed for light emitting

Very low power device

Heavily doped device

Question 9 of 18

Question 10 of 18

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

Reduce the losses

Run the motor with over load

Start the motor initially

Run the motor at synchronous speed

Question 10 of 18

Question 11 of 18

11. Which application requires only DC?

Electroplating

Stepping up of voltage

Operating induction motor

Operating repulsion motor

Question 11 of 18

Question 12 of 18

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

Produce a high magnetic-field to maintain a constant speed

Produce high voltage to initiate the rotation

Produces torque and runs near in synchronous speed

Produce high current to start rotate the motor

Question 12 of 18

Question 13 of 18

13. Which is the main application of synchronous motor?

Elevators

Paper rolling mills

AC to DC converter

Power factor correction device

Question 13 of 18

Question 14 of 18

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

Varying the line voltage

Decreasing the speed of motor

Increasing the speed of motor

Varying the field excitation

Question 14 of 18

Question 15 of 18

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

Defective pony motor

Open in damper winding

Insufficient excitation

Short in damper winding

Question 15 of 18

Question 16 of 18

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

Varying stator current in motor

Varying the motor load

Varying stator voltage in motor

Varying the rotor excitation

Question 16 of 18

Question 17 of 18

17. What is the advantage of motor generator set?

Noiseless

High efficiency

DC output voltage can be easily controlled

Low maintenance required

Question 17 of 18

Question 18 of 18

18. Which acts as both inverter and converter?

Metal rectifier

Mercury arc rectifier

Semi conductor diode

Synchronous converter

Question 18 of 18