MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 20 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The velocity of the dc machine at the final state is ________ |
| A. | E/Bl |
| B. | Bl/E |
| C. | EBl |
| D. | None of the mentioned |
| Answer» B. Bl/E | |
| 2. |
Pulsating torque frequency in universal motor is ________ |
| A. | 2f |
| B. | f |
| C. | f/2 |
| D. | 4f |
| Answer» B. f | |
| 3. |
For a universal motor, the rated supply current is 10A giving a rated torque of 100 N-m. If a current of 5A is applied, what will be generated torque vary to? |
| A. | 250 N-m |
| B. | 400 N-m |
| C. | 500 N-m |
| D. | 1000 N-m |
| Answer» C. 500 N-m | |
| 4. |
DC Motor torque depends on ________ |
| A. | geometry |
| B. | magnetic properties |
| C. | any of the mentioned |
| D. | both geometry and magnetic properties of the structure |
| Answer» E. | |
| 5. |
The cogging torque is absent in the permanent magnet dc machine is due to ________ |
| A. | non-magnetic nature of rotor |
| B. | magnetic nature of rotor |
| C. | absence of ac supply |
| D. | any of the mentioned |
| Answer» B. magnetic nature of rotor | |
| 6. |
If the torque is in the direction of rotation, the DC machine acts as ________ |
| A. | generator |
| B. | motor |
| C. | amplidyne |
| D. | any of the mentioned |
| Answer» B. motor | |
| 7. |
If the torque induced is zero in the dc machine, it can be said that ____________ |
| A. | current is zero |
| B. | flux can be zero |
| C. | current or flux=0 |
| D. | any of the mentioned |
| Answer» B. flux can be zero | |
| 8. |
The torque induced beyond the pole shoes in the DC machine is? |
| A. | 0 |
| B. | 2/pi *phi *i |
| C. | 4/pi *phi *i |
| D. | none of the mentioned |
| Answer» B. 2/pi *phi *i | |
| 9. |
DC_MOTOR_TORQUE_DEPENDS_ON?$ |
| A. | geometry |
| B. | magnetic properties |
| C. | any of the mentioned |
| D. | both geometry and magnetic properties of the structure |
| Answer» E. | |
| 10. |
THE_COGGING_TORQUE_IS_ABSENT_IN_THE_PERMANENT_MAGNET_DC_MACHINE_IS_DUE_TO?$ |
| A. | non-magnetic nature of rotor |
| B. | magnetic nature of rotor |
| C. | absence of ac supply |
| D. | any of the mentioned |
| Answer» B. magnetic nature of rotor | |
| 11. |
Pulsating torque frequency in universal motor$ |
| A. | 2f |
| B. | f |
| C. | f/2 |
| D. | 4f |
| Answer» B. f | |
| 12. |
For a universal motor, the rated supply current is 10A giving a rated torque of 100 N-m. If a current of 5A is applied, what will be generated torque vary to?$ |
| A. | 250 N-m |
| B. | 400 N-m |
| C. | 500 N-m |
| D. | 1000 N-m |
| Answer» C. 500 N-m | |
| 13. |
The velocity of the dc machine at the final state is |
| A. | E/Bl |
| B. | Bl/E |
| C. | EBl |
| D. | None of the mentioned |
| Answer» B. Bl/E | |
| 14. |
If the torque is in the direction of rotation, the DC machine acts a? |
| A. | generator |
| B. | motor |
| C. | amplidyne |
| D. | any of the mentioned |
| Answer» B. motor | |
| 15. |
The simple rotating loop between pole faces connected to a battery and resistor through a switch, the specifications of this machine are radius = 0.5m, length 1m, resistance = 0.3 ohms and magnitude strength = 0.25T is supplied with 120V. What is the steady state angular velocity at no-load? |
| A. | 480 rad/s |
| B. | 960 rad/s |
| C. | 320 rad/s |
| D. | 490 rad/s |
| Answer» B. 960 rad/s | |
| 16. |
If the torque induced is zero in the dc machine, it can be said that |
| A. | current is zero |
| B. | flux can be zero |
| C. | current or flux=0 |
| D. | any of the mentioned |
| Answer» B. flux can be zero | |
| 17. |
The simple rotating loop between pole faces connected to a battery and resistor through a switch, the specifications of this machine are radius = 0.5m, length 1m, resistance = 0.3 ohms and magnitude strength = 0.25T is supplied with 120V. What will be the magnitude of the following current at t=0+? |
| A. | 400A |
| B. | 200A |
| C. | 0 |
| D. | any of the mentioned |
| Answer» B. 200A | |
| 18. |
The simple rotating loop between pole faces connected to a battery and resistor through a switch, the specifications of this machine are radius = 0.5m, length 1m, resistance = 0.3 ohms and magnitude strength = 0.25T is supplied with 120V. Suddenly the switch is closed at t=0, what is observed in the circuit? |
| A. | Current will flow but zero induced EMF |
| B. | Current will not flow and zero induced EMF |
| C. | Current will not flow but EMF is induced |
| D. | Current will flow and EMF will also be induced |
| Answer» B. Current will not flow and zero induced EMF | |
| 19. |
The torque induced beyond the pole shoes in the DC machine is |
| A. | 0 |
| B. | 2/pi *phi *i |
| C. | 4/pi *phi *i |
| D. | none of the mentioned |
| Answer» B. 2/pi *phi *i | |
| 20. |
What is the principle of torque production in a dc machine? |
| A. | Lorentz’s law |
| B. | Lenz’s law |
| C. | Faraday’s law |
| D. | Self inductance |
| Answer» B. Lenz‚Äö√Ñ√∂‚àö√ë‚àö¬•s law | |