Question 1 of 18

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

Collects the delivered direct current

Helps to deliver without noise

Converts AC to DC

Reduces voltage drop

Question 1 of 18

Question 2 of 18

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

Varying the field excitation

Varying the line voltage

Increasing the speed of motor

Decreasing the speed of motor

Question 2 of 18

Question 3 of 18

3. Which is the main application of synchronous motor?

Power factor correction device

Elevators

Paper rolling mills

AC to DC converter

Question 3 of 18

Question 4 of 18

4. Which converting device can be over loaded?

Rectifier unit

Mercury arc rectifier

Rotary converter

Motor generator set

Question 4 of 18

Question 5 of 18

5. What is the function of inverter?

Smoothening A.C sine wave

Convert A.C to D.C

Convert D.C to A.C

Convert pulsating DC into pure D.C

Question 5 of 18

Question 6 of 18

6. Which converter is having high efficiency?

SCR converter

Motor generator set

Mercury arc rectifier

Rotary converter

Question 6 of 18

Question 7 of 18

7. Which application requires only DC?

Stepping up of voltage

Electroplating

Operating repulsion motor

Operating induction motor

Question 7 of 18

Question 8 of 18

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

Run the motor at synchronous speed

Reduce the losses in motor

Improve the power factor

Carry more load in motor

Question 8 of 18

Question 9 of 18

9. 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 a high magnetic-field to maintain a constant speed

Produce high voltage to initiate the rotation

Question 9 of 18

Question 10 of 18

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

Maintain power factor

Maintain constant speed

Start the synchronous motor

Excite the field winding

Question 10 of 18

Question 11 of 18

11. What is the name of the converter?

Motor-Generator set

Metal rectifier

Mercury arc rectifier

Rotary converter

Question 11 of 18

Question 12 of 18

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

Designed for light emitting

Heavily doped device

Very low power device

Very sensitive to temperature

Question 12 of 18

Question 13 of 18

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

Varying stator voltage in motor

Varying the rotor excitation

Varying the motor load

Varying stator current in motor

Question 13 of 18

Question 14 of 18

14. What is the name of the converter?

Metal rectifier

Rotary converter

Silicon controlled rectifier

Mercury arc rectifier

Question 14 of 18

Question 15 of 18

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

Start the motor initially

Reduce the losses

Run the motor at synchronous speed

Run the motor with over load

Question 15 of 18

Question 16 of 18

16. What is the advantage of motor generator set?

DC output voltage can be easily controlled

Noiseless

Low maintenance required

High efficiency

Question 16 of 18

Question 17 of 18

17. Which acts as both inverter and converter?

Metal rectifier

Mercury arc rectifier

Synchronous converter

Semi conductor diode

Question 17 of 18

Question 18 of 18

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

Short in damper winding

Open in damper winding

Insufficient excitation

Defective pony motor

Question 18 of 18