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. |
Vt= Ea– Ia(Ra+ Rse) is the equation for _______________ |
| A. | Short shunt compound motoring mode |
| B. | Short shunt compound generating mode |
| C. | long shunt compound motoring mode |
| D. | Cannot be determined |
| E. | is the equation for _______________a) Short shunt compound motoring modeb) Short shunt compound generating modec) long shunt compound motoring moded) Cannot be determined |
| Answer» C. long shunt compound motoring mode | |
| 2. |
For a long-shunt compound motoring, which of the following equation is correct? |
| A. | Vt= Ea+ Ia(Ra+ Rse) |
| B. | Vt= Ea– Ia(Ra+ Rse) |
| C. | Vt= Ea+ Ia(Ra– Rse) |
| D. | Vt= -Ea+ Ia(Ra+ Rs |
| E. | Vt= Ea– Ia(Ra+ Rse)c) Vt= Ea+ Ia(Ra– Rse)d) Vt= -Ea+ Ia(Ra+ Rse) |
| Answer» B. Vt= Ea– Ia(Ra+ Rse) | |
| 3. |
If a DC compound machine connected as a motor is about to use as a generator, we reverse the series field connections. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4. |
How short shunt and long shunt compound winding is selected? |
| A. | Mechanical considerations |
| B. | Switch reversal |
| C. | Performance |
| D. | Mechanical considerations and switch reversal |
| Answer» E. | |
| 5. |
HOW_SHORT_SHUNT_AND_LONG_SHUNT_COMPOUND_WINDING_IS_SELECTED??$ |
| A. | Mechanical considerations |
| B. | Switch reversal |
| C. | Performance |
| D. | Mechanical considerations and switch reversal |
| Answer» E. | |
| 6. |
For a long-shunt compound motoring, which of the following equation is correct?$ |
| A. | V<sub>t</sub>= E<sub>a</sub>+ I<sub>a</sub>(R<sub>a</sub>+ R<sub>se</sub>) |
| B. | V<sub>t</sub>= E<sub>a</sub>– I<sub>a</sub>(R<sub>a</sub>+ R<sub>se</sub>) |
| C. | V<sub>t</sub>= E<sub>a</sub>+ I<sub>a</sub>(R<sub>a</sub>– R<sub>se</sub>) |
| D. | V<sub>t</sub>= -E<sub>a</sub>+ I<sub>a</sub>(R<sub>a</sub>+ R<sub>se</sub>) |
| Answer» B. V<sub>t</sub>= E<sub>a</sub>‚Äö√Ñ√∂‚àö√ë‚àö¬® I<sub>a</sub>(R<sub>a</sub>+ R<sub>se</sub>) | |
| 7. |
If_a_DC_compound_machine_connected_as_a_motor_is_about_to_use_as_a_generator,_we_reverse_the_series_field_connections.$ |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8. |
The generator is called flat compounded if _____________ |
| A. | The series field ampere turns are such as to produce the same voltage at rated load as at no load |
| B. | The series field turns are such as that the no load voltage is smaller than the rated load voltage |
| C. | The rated voltage is less than the no load voltage |
| D. | Cannot be determined |
| Answer» B. The series field turns are such as that the no load voltage is smaller than the rated load voltage | |
| 9. |
How shunt field is controlled? |
| A. | Diverter resistor in parallel |
| B. | Tapped field winding |
| C. | Series regulating resistance |
| D. | Other methods |
| Answer» D. Other methods | |
| 10. |
Vt= Ea– Ia(Ra+ Rse) is the equation for _______________$ |
| A. | Short shunt compound motoring mode |
| B. | Short shunt compound generating mode |
| C. | long shunt compound motoring mode |
| D. | Cannot be determined |
| Answer» C. long shunt compound motoring mode | |
| 11. |
Which winding in compound excitation is responsible for change in air gap flux per pole? |
| A. | Series |
| B. | Parallel |
| C. | Interconnected |
| D. | No coil is responsible |
| Answer» B. Parallel | |
| 12. |
In differential compound excited machine, what is the variation in air gap flux per pole with respect to armature current? |
| A. | Increases |
| B. | Decreases |
| C. | Remains constant |
| D. | Always varies |
| Answer» C. Remains constant | |
| 13. |
In which type of excitation air gap flux increases with armature current? |
| A. | Differential compound |
| B. | Cumulative compound |
| C. | Differential and Cumulative |
| D. | Cannot be determined |
| Answer» C. Differential and Cumulative | |
| 14. |
In compound excitation, which winding/s is/are excited? |
| A. | Shunt |
| B. | Series |
| C. | Both |
| D. | Cannot be determined |
| Answer» D. Cannot be determined | |
| 15. |
Which is more practical method used in control of series field? |
| A. | Diverter |
| B. | Tappings |
| C. | Switch relay |
| D. | Cannot be determined |
| Answer» C. Switch relay | |
| 16. |
Which winding have higher resistance? |
| A. | Shunt field |
| B. | Series field |
| C. | Both have same number of turns |
| D. | Depends on requirement |
| Answer» B. Series field | |
| 17. |
Which winding contains wire with higher thickness? |
| A. | Shunt field |
| B. | Series field |
| C. | Both have same number of turns |
| D. | Depends on requirement |
| Answer» C. Both have same number of turns | |
| 18. |
Which winding has large number of turns? |
| A. | Shunt field |
| B. | Series field |
| C. | Both have same number of turns |
| D. | Depends on requirement |
| Answer» B. Series field | |