Question 1 of 18

1. Which application requires only DC?

Electroplating

Stepping up of voltage

Operating repulsion motor

Operating induction motor

Question 1 of 18

Question 2 of 18

2. What is the function of inverter?

Convert A.C to D.C

Convert D.C to A.C

Smoothening A.C sine wave

Convert pulsating DC into pure D.C

Question 2 of 18

Question 3 of 18

3. Which converting device can be over loaded?

Rectifier unit

Motor generator set

Mercury arc rectifier

Rotary converter

Question 3 of 18

Question 4 of 18

4. What is the advantage of motor generator set?

Low maintenance required

High efficiency

Noiseless

DC output voltage can be easily controlled

Question 4 of 18

Question 5 of 18

5. Which acts as both inverter and converter?

Metal rectifier

Semi conductor diode

Mercury arc rectifier

Synchronous converter

Question 5 of 18

Question 6 of 18

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

Reduces voltage drop

Helps to deliver without noise

Converts AC to DC

Collects the delivered direct current

Question 6 of 18

Question 7 of 18

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

Defective pony motor

Open in damper winding

Insufficient excitation

Short in damper winding

Question 7 of 18

Question 8 of 18

8. Which is the main application of synchronous motor?

Power factor correction device

Paper rolling mills

AC to DC converter

Elevators

Question 8 of 18

Question 9 of 18

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

Reduce the losses in motor

Run the motor at synchronous speed

Improve the power factor

Carry more load in motor

Question 9 of 18

Question 10 of 18

10. Which converter is having high efficiency?

Mercury arc rectifier

Rotary converter

SCR converter

Motor generator set

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 high voltage to initiate the rotation

Produce a high magnetic-field to maintain a constant speed

Question 11 of 18

Question 12 of 18

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

Varying the rotor excitation

Varying the motor load

Varying stator voltage in motor

Varying stator current in motor

Question 12 of 18

Question 13 of 18

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

Very low power device

Heavily doped device

Designed for light emitting

Very sensitive to temperature

Question 13 of 18

Question 14 of 18

14. What is the name of the converter?

Metal rectifier

Motor-Generator set

Rotary converter

Mercury arc rectifier

Question 14 of 18

Question 15 of 18

15. What is the name of the converter?

Rotary converter

Mercury arc rectifier

Silicon controlled rectifier

Metal rectifier

Question 15 of 18

Question 16 of 18

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

Excite the field winding

Start the synchronous motor

Maintain power factor

Maintain constant speed

Question 16 of 18

Question 17 of 18

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

Start the motor initially

Run the motor with over load

Run the motor at synchronous speed

Reduce the losses

Question 17 of 18

Question 18 of 18

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

Varying the field excitation

Varying the line voltage

Decreasing the speed of motor

Increasing the speed of motor

Question 18 of 18