Question 1 of 18

1. Which is the main application of synchronous motor?

AC to DC converter

Power factor correction device

Paper rolling mills

Elevators

Question 1 of 18

Question 2 of 18

2. 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 2 of 18

Question 3 of 18

3. Which application requires only DC?

Electroplating

Operating repulsion motor

Operating induction motor

Stepping up of voltage

Question 3 of 18

Question 4 of 18

4. What is the advantage of motor generator set?

Noiseless

DC output voltage can be easily controlled

Low maintenance required

High efficiency

Question 4 of 18

Question 5 of 18

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

Maintain constant speed

Excite the field winding

Maintain power factor

Start the synchronous motor

Question 5 of 18

Question 6 of 18

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

Improve the power factor

Carry more load in motor

Run the motor at synchronous speed

Reduce the losses in motor

Question 6 of 18

Question 7 of 18

7. Which acts as both inverter and converter?

Metal rectifier

Mercury arc rectifier

Synchronous converter

Semi conductor diode

Question 7 of 18

Question 8 of 18

8. What is the function of inverter?

Convert D.C to A.C

Convert pulsating DC into pure D.C

Smoothening A.C sine wave

Convert A.C to D.C

Question 8 of 18

Question 9 of 18

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

Varying the motor load

Varying stator current in motor

Varying the rotor excitation

Varying stator voltage in motor

Question 9 of 18

Question 10 of 18

10. 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 10 of 18

Question 11 of 18

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

Short in damper winding

Open in damper winding

Defective pony motor

Insufficient excitation

Question 11 of 18

Question 12 of 18

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

Reduces voltage drop

Helps to deliver without noise

Collects the delivered direct current

Converts AC to DC

Question 12 of 18

Question 13 of 18

13. Which converting device can be over loaded?

Rectifier unit

Mercury arc rectifier

Motor generator set

Rotary converter

Question 13 of 18

Question 14 of 18

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

Varying the field excitation

Decreasing the speed of motor

Increasing the speed of motor

Varying the line voltage

Question 14 of 18

Question 15 of 18

15. What is the name of the converter?

Rotary converter

Silicon controlled rectifier

Metal rectifier

Mercury arc rectifier

Question 15 of 18

Question 16 of 18

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

Reduce the losses

Run the motor with over load

Run the motor at synchronous speed

Start the motor initially

Question 16 of 18

Question 17 of 18

17. What is the name of the converter?

Motor-Generator set

Rotary converter

Mercury arc rectifier

Metal rectifier

Question 17 of 18

Question 18 of 18

18. Which converter is having high efficiency?

Rotary converter

SCR converter

Mercury arc rectifier

Motor generator set

Question 18 of 18