MCQOPTIONS
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MCQOPTIONS
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Electric Drives knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The field diverter resistance for a DC series motor is kept ________ |
| A. | High |
| B. | Low |
| C. | zero |
| D. | one |
| Answer» C. zero | |
| 2. |
For a given torque, increasing diverter resistance of a DC series motor causes the ________ |
| A. | decrease in speed and less armature current |
| B. | decrease in speed but armature current remains the same |
| C. | increase in speed and more armature current |
| D. | increase in speed but armature current remains the same |
| Answer» B. decrease in speed but armature current remains the same | |
| 3. |
Calculate the current in DC series field winding using the following data: Ia=3 A. |
| A. | 4 A |
| B. | 2 A |
| C. | 3 A |
| D. | 6 A |
| Answer» D. 6 A | |
| 4. |
The shape of the current-torque current characteristics in DC series motor is a __________ |
| A. | Rectangular Hyperbolic |
| B. | Parabola |
| C. | Circle |
| D. | Ellipse |
| Answer» C. Circle | |
| 5. |
DC series motors are used where the high ________ torque is required. |
| A. | Maximum |
| B. | Minimum |
| C. | Starting |
| D. | Stalling |
| Answer» D. Stalling | |
| 6. |
The shape of the speed-torque current characteristics in DC series motor are __________ |
| A. | Rectangular Hyperbolic |
| B. | Parabola |
| C. | Circle |
| D. | Ellipse |
| Answer» B. Parabola | |
| 7. |
The shape of the speed-armature current characteristics in DC series motor are __________ |
| A. | Hyperbolic |
| B. | Parabola |
| C. | Circle |
| D. | Ellipse |
| Answer» B. Parabola | |
| 8. |
Calculate the flux produced by the DC series field winding using the following data: Ia=5 A, N=23, R=23. |
| A. | 5 Wb |
| B. | 6 Wb |
| C. | 9 Wb |
| D. | 8 Wb |
| Answer» B. 6 Wb | |
| 9. |
In dynamic braking, DC series motor behaves as a ____________ |
| A. | Separately excited motor |
| B. | Transformer |
| C. | Induction motor |
| D. | Thyristor |
| Answer» B. Transformer | |
| 10. |
Calculate the time period of the waveform x(t)=1cot( t+7 ). |
| A. | 0.5 sec |
| B. | 1 sec |
| C. | 3 sec |
| D. | 5 sec |
| Answer» C. 3 sec | |
| 11. |
At the starting, the field is very strong but it decreases with time because of the ________ |
| A. | Reduction in armature current |
| B. | Increase in armature current |
| C. | Reduction in speed |
| D. | Increase in speed |
| Answer» B. Increase in armature current | |
| 12. |
For faster braking, the series field is separated from the armature circuit. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 13. |
In DC series machine is directly proportional to Ia. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 14. |
Dynamic braking requires a strong _________ |
| A. | Magnetic field |
| B. | Electrostatic field |
| C. | Nuclear field |
| D. | Gravitational field |
| Answer» B. Electrostatic field | |