MCQOPTIONS
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MCQOPTIONS
This section includes 12 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. |
Similarity between Hopkinonson s and field s test is that _______ |
| A. | both need similar mechanically coupled motor |
| B. | both need similar electrically coupled motor |
| C. | regenerative power |
| D. | negligible power |
| Answer» B. both need similar electrically coupled motor | |
| 2. |
Swineburne s test is applicable to those machines in which flux is practically _______ |
| A. | constant |
| B. | linear |
| C. | non-linear |
| D. | none of the mentioned |
| Answer» B. linear | |
| 3. |
The efficiency in the swineburne s test can be found. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4. |
Which is the most appropriate relation to find efficiency of the generator? |
| A. | output/(output + losses) |
| B. | (output losses)/input |
| C. | (output losses)/(output + losses) |
| D. | any of the mentioned |
| Answer» B. (output losses)/input | |
| 5. |
Hopkinson s test is also called regenerative test due to ____________ |
| A. | energy of one machine is used to drive other |
| B. | feedback |
| C. | losses are least |
| D. | extra motor is used |
| Answer» B. feedback | |
| 6. |
In the Hopkinson s test on two DC machines. Machine A has field current of 1.4A and B has field current of 1.3A. Which machine acts as generator? |
| A. | B |
| B. | A |
| C. | A,B |
| D. | None of the mentioned |
| Answer» C. A,B | |
| 7. |
In the hopkinson s test on two DC machines. Machine A has field current of 1.4A and B has field current of 1.3A. Which machine acts as motor? |
| A. | B |
| B. | A |
| C. | A, B |
| D. | None of the mentioned |
| Answer» B. A | |
| 8. |
If the field current and armature current are reversed, then the __________ |
| A. | direction of rotation remains same |
| B. | direction of rotation reverses |
| C. | stops |
| D. | none of the mentioned |
| Answer» B. direction of rotation reverses | |
| 9. |
______ test is used for determining the efficiency of a traction motor. |
| A. | Field |
| B. | Retardation |
| C. | Hopkinson |
| D. | Swineburne s |
| Answer» B. Retardation | |
| 10. |
The quantities needed to complete retardation test are/is _________ |
| A. | dw/dt and moment of inertia |
| B. | dw/dt |
| C. | current |
| D. | any of the mentioned |
| Answer» B. dw/dt | |
| 11. |
What is the main concern before doing hopkinson s test for finding efficiency? |
| A. | needs one motor and one generator is that it |
| B. | ignores iron and stray losses |
| C. | needs one motor |
| D. | requires identical shunt machines |
| Answer» E. | |
| 12. |
A dc motor is connected in the short-shunt configuration, but the series and the shunt windings get interchanged by mistake and the motor is connected to the rated voltage? |
| A. | neither of the windings get short-circuit |
| B. | series winding gets overloaded |
| C. | shunt winding gets overloaded |
| D. | both of the winding get overloaded |
| Answer» B. series winding gets overloaded | |