MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Dc Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Retardation curve is ______________ |
| A. | Starting from origin |
| B. | Starts from some positive value and increasing |
| C. | Starts from some positive curve and stays constant |
| D. | Starts from some positive value and decreases |
| Answer» E. | |
| 2. |
In retardation test _____________ |
| A. | Motor switch is made ON and various speed readings are taken |
| B. | At rated speed various speed readings are taken out at different times |
| C. | Motor switch is made OFF at rated speed and various speed readings are taken |
| D. | Some readings are taken while speed is building up and some readings while speed is lowering down |
| Answer» D. Some readings are taken while speed is building up and some readings while speed is lowering down | |
| 3. |
While carrying out retardation test, if t is equal to time constant then _____________ |
| A. | Speed increases to 36.8% of its initial value |
| B. | Speed reduces to 36.8% of its initial value |
| C. | Speed reduces to 26.8% of its initial value |
| D. | Speed reduces to 46.8% of its initial value |
| Answer» C. Speed reduces to 26.8% of its initial value | |
| 4. |
Which of the following is not a disadvantage of a Swinburne s test? |
| A. | The stray-load losses can t be determined by this test |
| B. | Steady temperature rise can t be determined |
| C. | Does not give results about satisfactory commutation |
| D. | Machine gets damaged |
| Answer» E. | |
| 5. |
Efficiency calculated by Swinburne s test is _____________ |
| A. | Exactly equal |
| B. | Over-estimated |
| C. | Under-estimated |
| D. | Depends on the manual errors |
| Answer» C. Under-estimated | |
| 6. |
What is the purpose of performing retardation test after Swinburne s test? |
| A. | To find stray load loss |
| B. | To find variable losses |
| C. | To separate out windage and friction losses |
| D. | To find shunt field losses |
| Answer» D. To find shunt field losses | |
| 7. |
In order to run motor on rated speed while carrying out Swinburne s test we add ______________ |
| A. | Resistance in parallel with armature |
| B. | Resistance in series with armature |
| C. | Inductor in series with armature |
| D. | Capacitor in parallel with armature |
| Answer» C. Inductor in series with armature | |
| 8. |
While carrying out Swinburne s test at rated armature voltage motor will run at ____________ |
| A. | Speed equal to rated speed |
| B. | Speed greater than rated speed |
| C. | Speed less than rated speed |
| D. | Can run anywhere |
| Answer» C. Speed less than rated speed | |
| 9. |
Which losses can be identified from Swinburne s test? |
| A. | No-load core loss |
| B. | Windage and friction loss |
| C. | No-load and windage and friction loss |
| D. | Stray load loss |
| Answer» D. Stray load loss | |
| 10. |
1.Swinburne s test can be carried out on all DC motors. |
| A. | True |
| B. | False |
| Answer» C. | |