Question 1 of 18

1. Which acts as both inverter and converter?

Metal rectifier

Semi conductor diode

Synchronous converter

Mercury arc rectifier

Question 1 of 18

Question 2 of 18

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

Start the synchronous motor

Excite the field winding

Maintain power factor

Maintain constant speed

Question 2 of 18

Question 3 of 18

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

Varying stator voltage in motor

Varying the rotor excitation

Varying stator current in motor

Varying the motor load

Question 3 of 18

Question 4 of 18

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

Short in damper winding

Insufficient excitation

Defective pony motor

Open in damper winding

Question 4 of 18

Question 5 of 18

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

Reduces voltage drop

Collects the delivered direct current

Helps to deliver without noise

Converts AC to DC

Question 5 of 18

Question 6 of 18

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

Run the motor with over load

Reduce the losses

Run the motor at synchronous speed

Start the motor initially

Question 6 of 18

Question 7 of 18

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

Increasing the speed of motor

Decreasing the speed of motor

Varying the field excitation

Varying the line voltage

Question 7 of 18

Question 8 of 18

8. What is the name of the converter?

Metal rectifier

Motor-Generator set

Rotary converter

Mercury arc rectifier

Question 8 of 18

Question 9 of 18

9. Which application requires only DC?

Operating repulsion motor

Operating induction motor

Stepping up of voltage

Electroplating

Question 9 of 18

Question 10 of 18

10. What is the name of the converter?

Mercury arc rectifier

Silicon controlled rectifier

Rotary converter

Metal rectifier

Question 10 of 18

Question 11 of 18

11. 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 11 of 18

Question 12 of 18

12. Which converting device can be over loaded?

Rectifier unit

Rotary converter

Motor generator set

Mercury arc rectifier

Question 12 of 18

Question 13 of 18

13. What is the function of inverter?

Smoothening A.C sine wave

Convert D.C to A.C

Convert pulsating DC into pure D.C

Convert A.C to D.C

Question 13 of 18

Question 14 of 18

14. What is the advantage of motor generator set?

Low maintenance required

DC output voltage can be easily controlled

Noiseless

High efficiency

Question 14 of 18

Question 15 of 18

15. 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 15 of 18

Question 16 of 18

16. Which is the main application of synchronous motor?

Elevators

Power factor correction device

AC to DC converter

Paper rolling mills

Question 16 of 18

Question 17 of 18

17. Which converter is having high efficiency?

SCR converter

Rotary converter

Mercury arc rectifier

Motor generator set

Question 17 of 18

Question 18 of 18

18. 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 18 of 18