MCQOPTIONS
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MCQOPTIONS
This section includes 7 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. |
The reactive power output of a synchronous generator is limited by _________ |
| A. | armature current and field current |
| B. | field current and load angle |
| C. | load angle and excitation |
| D. | armature current only |
| Answer» B. field current and load angle | |
| 2. |
In a 3-phase cylindrical-rotor alternator, synchronous reactance is sum of _____________ |
| A. | mutual and leakage reactance |
| B. | magnetizing and leakage reactance |
| C. | magnetizing and mutual reactance |
| D. | mutual, magnetizing and leakage reactance |
| Answer» B. magnetizing and leakage reactance | |
| 3. |
The given variable losses are 5kW fr a 500 KVA, 11 kV, 3-phase star connected alternator having armature resistance of 4 ohms. Calculate the full load armature current per phase. |
| A. | 26.24 A |
| B. | 20.41 A |
| C. | 79 A |
| D. | 40 A |
| Answer» B. 20.41 A | |
| 4. |
The given variable losses are 5kW fr a 500 KVA, 11 kV, 3-phase star connected alternator having armature resistance of 4 ohms. Calculate the current at which maximum efficiency occurs? |
| A. | 20.4A |
| B. | 10.2A |
| C. | 40A |
| D. | 26A |
| Answer» B. 10.2A | |
| 5. |
Rotational losses vary as follows with respect to field current. |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3a.png"><img alt="Rotational losses vary as shown in the graph with respect to field current - option a" class="alignnone size-full wp-image-160977" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3b.png"><img alt="Rotational losses vary as shown in the graph with respect to field current - option b" class="alignnone size-full wp-image-160978" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3c.png"><img alt="Rotational losses vary as shown in the graph with respect to field current - option c" class="alignnone size-full wp-image-160979" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3d.png"><img alt="Rotational losses vary as shown in the graph with respect to field current - option d" class="alignnone size-full wp-image-160980" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3b.png"><img alt="Rotational losses vary as shown in the graph with respect to field current - option b" class="alignnone size-full wp-image-160978" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q3b.png" width="300"/></a> | |
| 6. |
The open circuit voltage and open circuit core loss variation is? |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2a.png"><img alt="The open circuit voltage & open circuit core loss variation - option a" class="alignnone size-full wp-image-160973" height="174" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2b.png"><img alt="The open circuit voltage & open circuit core loss variation - option b" class="alignnone size-full wp-image-160974" height="189" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2c.png"><img alt="The open circuit voltage & open circuit core loss variation - option c" class="alignnone size-full wp-image-160975" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2d.png"><img alt="The open circuit voltage & open circuit core loss variation - option d" class="alignnone size-full wp-image-160976" height="174" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2b.png"><img alt="The open circuit voltage & open circuit core loss variation - option b" class="alignnone size-full wp-image-160974" height="189" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-entrance-exams-q2b.png" width="300"/></a> | |
| 7. |
The short circuit load losses is/are ______________ |
| A. | direct load loss and stray load losses |
| B. | direct load loss |
| C. | stray load losses |
| D. | field current loss |
| Answer» B. direct load loss | |