Question 1 of 18

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

Very sensitive to temperature

Heavily doped device

Very low power device

Designed for light emitting

Question 1 of 18

Question 2 of 18

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

Short in damper winding

Defective pony motor

Insufficient excitation

Open in damper winding

Question 2 of 18

Question 3 of 18

3. What is the name of the converter?

Metal rectifier

Motor-Generator set

Rotary converter

Mercury arc rectifier

Question 3 of 18

Question 4 of 18

4. 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 4 of 18

Question 5 of 18

5. What is the advantage of motor generator set?

High efficiency

DC output voltage can be easily controlled

Low maintenance required

Noiseless

Question 5 of 18

Question 6 of 18

6. What is the name of the converter?

Silicon controlled rectifier

Mercury arc rectifier

Metal rectifier

Rotary converter

Question 6 of 18

Question 7 of 18

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

Reduce the losses

Start the motor initially

Run the motor with over load

Run the motor at synchronous speed

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

Convert A.C to D.C

Smoothening A.C sine wave

Question 8 of 18

Question 9 of 18

9. Which converter is having high efficiency?

Mercury arc rectifier

Motor generator set

SCR converter

Rotary converter

Question 9 of 18

Question 10 of 18

10. Which is the main application of synchronous motor?

Power factor correction device

Paper rolling mills

AC to DC converter

Elevators

Question 10 of 18

Question 11 of 18

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

Reduce the losses in motor

Run the motor at synchronous speed

Carry more load in motor

Improve the power factor

Question 11 of 18

Question 12 of 18

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

Varying the rotor excitation

Varying stator voltage in motor

Varying the motor load

Varying stator current in motor

Question 12 of 18

Question 13 of 18

13. Which acts as both inverter and converter?

Semi conductor diode

Synchronous converter

Mercury arc rectifier

Metal rectifier

Question 13 of 18

Question 14 of 18

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

Excite the field winding

Start the synchronous motor

Maintain constant speed

Maintain power factor

Question 14 of 18

Question 15 of 18

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

Varying the line voltage

Decreasing the speed of motor

Varying the field excitation

Increasing the speed of motor

Question 15 of 18

Question 16 of 18

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

Produces torque and runs near in synchronous speed

Produce high voltage to initiate the rotation

Produce a high magnetic-field to maintain a constant speed

Produce high current to start rotate the motor

Question 16 of 18

Question 17 of 18

17. Which application requires only DC?

Operating induction motor

Operating repulsion motor

Electroplating

Stepping up of voltage

Question 17 of 18

Question 18 of 18

18. Which converting device can be over loaded?

Rectifier unit

Motor generator set

Mercury arc rectifier

Rotary converter

Question 18 of 18