MCQOPTIONS
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MCQOPTIONS
This section includes 18 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. |
By changing the polarity of the armature of failed self-exciting machine, machine can be started. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
Which of the following is not a reason, behind failing of self-exciting machine? |
| A. | Residual magnetism is absent |
| B. | Negative feedback |
| C. | Field resistance value is more than critical resistance value |
| D. | Armature resistance is non-zero |
| Answer» E. | |
| 3. |
DC generator will not self-excite in __________ |
| A. | Positive feedback |
| B. | Negative feedback |
| C. | Zero Feedback |
| D. | Doesn’t depend on feedback |
| Answer» C. Zero Feedback | |
| 4. |
No-load voltage can’t be defined where _____________ |
| A. | Field resistance line lies below the magnetization linear line |
| B. | Field resistance line intersects the magnetization linear line |
| C. | Field resistance line coincides the magnetization linear line |
| D. | Defined everywhere |
| Answer» D. Defined everywhere | |
| 5. |
For a self-excited DC shunt generator Ia = _____________ |
| A. | IL – If |
| B. | IL + IL |
| C. | – IL – IL |
| D. | – IL + IL |
| Answer» C. – IL – IL | |
| 6. |
DC_GENERATOR_WILL_NOT_SELF-EXCITE_IN___________?$ |
| A. | Positive feedback |
| B. | Negative feedback |
| C. | Zero Feedback |
| D. | Doesn’t depend on feedback |
| Answer» C. Zero Feedback | |
| 7. |
By changing the polarity of the armature of failed self-exciting machine, machine can be started.$ |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8. |
Which of the following is not a reason, behind failing of self-exciting machine?$ |
| A. | Residual magnetism is absent |
| B. | Negative feedback |
| C. | Field resistance value is more than critical resistance value |
| D. | Armature resistance is non-zero |
| Answer» E. | |
| 9. |
Which of the following will be useful to generate positive feedback? |
| A. | Increasing the field resistance |
| B. | Increasing the armature resistance |
| C. | Decreasing the armature resistance |
| D. | Changing the shaft direction |
| Answer» E. | |
| 10. |
No-load voltage observed at two different field resistance values, is V1 < V2. What will be the relation in speed if field resistance is kept same for both cases? |
| A. | N<sub>1</sub> < N<sub>2</sub> |
| B. | N<sub>1</sub> = N<sub>1</sub> |
| C. | N<sub>1</sub> > N<sub>1</sub> |
| D. | Can’t determine from no-load voltage |
| Answer» B. N<sub>1</sub> = N<sub>1</sub> | |
| 11. |
No-load voltage observed at two different field resistance values, is V1 < V2. What will be the relation in field resistance values? |
| A. | Rf<sub>1</sub> < Rf<sub>2</sub> |
| B. | Rf<sub>1</sub> = Rf<sub>1</sub> |
| C. | Rf<sub>1</sub> > Rf<sub>1</sub> |
| D. | Can’t determine from no-load voltage |
| Answer» D. Can‚Äö√Ñ√∂‚àö√ë‚àö¬•t determine from no-load voltage | |
| 12. |
Machine does not excite to an appreciable value when ___________ |
| A. | Field resistance is less than critical resistance |
| B. | Field resistance is more than critical resistance |
| C. | In both cases a and b |
| D. | Depends on other parameters |
| Answer» C. In both cases a and b | |
| 13. |
No-load voltage can’t be defined where _____________$ |
| A. | Field resistance line lies below the magnetization linear line |
| B. | Field resistance line intersects the magnetization linear line |
| C. | Field resistance line coincides the magnetization linear line |
| D. | Defined everywhere |
| Answer» D. Defined everywhere | |
| 14. |
What will happen if field resistance is decreased? |
| A. | No load voltage will decrease |
| B. | No load voltage will increase |
| C. | No change in no load voltage |
| D. | Field current will decrease |
| Answer» C. No change in no load voltage | |
| 15. |
Intersection of Rf line and magnetization curve will give _____________ |
| A. | No load terminal voltage |
| B. | Field current at no load |
| C. | Both a and b |
| D. | Not specific data |
| Answer» D. Not specific data | |
| 16. |
For self-excited DC generator, field circuit curve in the OCC will be __________ |
| A. | Straight line not passing through the origin with +ve slope |
| B. | Straight line passing through the origin |
| C. | Straight line not passing through the origin with -ve slope |
| D. | Increasing curve |
| Answer» C. Straight line not passing through the origin with -ve slope | |
| 17. |
For a self-excited DC shunt generator Ia = _____________ |
| A. | I<sub>L</sub> – I<sub>f</sub> |
| B. | I<sub>L</sub> + I<sub>L</sub> |
| C. | – I<sub>L</sub> – I<sub>L</sub> |
| D. | – I<sub>L</sub> + I<sub>L</sub> |
| Answer» C. ‚Äö√Ñ√∂‚àö√ë‚àö¬® I<sub>L</sub> ‚Äö√Ñ√∂‚àö√ë‚àö¬® I<sub>L</sub> | |
| 18. |
What is Self-excitation in DC shunt generator? |
| A. | Field winding is connected in series of armature |
| B. | Field winding is connected in parallel of armature |
| C. | Field winding is not connected to the armature |
| D. | Field Winding is not excited |
| Answer» C. Field winding is not connected to the armature | |