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. |
A 3-phase, 50 Hz, 6-pole induction motor has a shaft output of 10kW at 930 rpm. Friction and windage losses is 1% of the output. Total stator losses is 600W. What is the stator input? |
| A. | 10860 W |
| B. | 10100 W |
| C. | 11460 W |
| D. | 11000 W |
| Answer» D. 11000 W | |
| 2. |
A 3-phase, 50 Hz, 6-pole induction motor has a shaft output of 10kW at 930 rpm. Friction and windage losses is 1% of the output. Total stator losses is 600W. What is the rotor input? |
| A. | 10860 W |
| B. | 10100 W |
| C. | 11460 W |
| D. | 11000 W |
| Answer» B. 10100 W | |
| 3. |
Slip vs the torque developed in an induction motor is? |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12a.png"><img alt="Slip vs the torque developed in an induction motor - option a" class="alignnone size-full wp-image-161072" height="224" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12b.png"><img alt="Slip vs the torque developed in an induction motor - option b" class="alignnone size-full wp-image-161073" height="222" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12c.png"><img alt="Slip vs the torque developed in an induction motor - option c" class="alignnone size-full wp-image-161074" height="232" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12d.png"><img alt="Slip vs the torque developed in an induction motor - option d" class="alignnone size-full wp-image-161075" height="223" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12b.png"><img alt="Slip vs the torque developed in an induction motor - option b" class="alignnone size-full wp-image-161073" height="222" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q12b.png" width="300"/></a> | |
| 4. |
The stator current of the induction motor is given by which of the below? |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11a.png"><img alt="The stator current of the induction motor - option a" class="alignnone size-full wp-image-161068" height="185" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11b.png"><img alt="The stator current of the induction motor - option b" class="alignnone size-full wp-image-161069" height="223" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11c.png"><img alt="The stator current of the induction motor - option c" class="alignnone size-full wp-image-161070" height="204" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11d.png"><img alt="The stator current of the induction motor - option d" class="alignnone size-full wp-image-161071" height="208" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11b.png"><img alt="The stator current of the induction motor - option b" class="alignnone size-full wp-image-161069" height="223" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q11b.png" width="300"/></a> | |
| 5. |
Four students had been conducting conducting experiments on the same induction motor for its efficiency characteristics. Which student has taken the best results? |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10a.png"><img alt="The results on the same induction motor for its efficiency characteristics - option a" class="alignnone size-full wp-image-161064" height="188" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10b.png"><img alt="The results on the same induction motor for its efficiency characteristics - option b" class="alignnone size-full wp-image-161065" height="181" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10c.png"><img alt="The results on the same induction motor for its efficiency characteristics - option c" class="alignnone size-full wp-image-161066" height="197" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10d.png"><img alt="The results on the same induction motor for its efficiency characteristics - option d" class="alignnone size-full wp-image-161067" height="206" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10b.png"><img alt="The results on the same induction motor for its efficiency characteristics - option b" class="alignnone size-full wp-image-161065" height="181" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q10b.png" width="300"/></a> | |
| 6. |
The power factor variation of the 3-phase induction motor is given by? |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9a.png"><img alt="The power factor variation of the 3-phase induction motor - option a" class="alignnone size-full wp-image-161060" height="185" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9b.png"><img alt="The power factor variation of the 3-phase induction motor - option b" class="alignnone size-full wp-image-161061" height="219" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9c.png"><img alt="The power factor variation of the 3-phase induction motor - option c" class="alignnone size-full wp-image-161062" height="201" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9d.png"><img alt="The power factor variation of the 3-phase induction motor - option d" class="alignnone size-full wp-image-161063" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9b.png"><img alt="The power factor variation of the 3-phase induction motor - option b" class="alignnone size-full wp-image-161061" height="219" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q9b.png" width="300"/></a> | |
| 7. |
The speed-power output characteristic of a 3-phase induction motor is? |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8a.png"><img alt="The speed-power output characteristic of a 3-phase induction motor - option a" class="alignnone size-full wp-image-161056" height="202" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8b.png"><img alt="The speed-power output characteristic of a 3-phase induction motor - option b" class="alignnone size-full wp-image-161057" height="195" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8c.png"><img alt="The speed-power output characteristic of a 3-phase induction motor - option c" class="alignnone size-full wp-image-161058" height="180" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8d.png"><img alt="The speed-power output characteristic of a 3-phase induction motor - option d" class="alignnone size-full wp-image-161059" height="186" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8b.png"><img alt="The speed-power output characteristic of a 3-phase induction motor - option b" class="alignnone size-full wp-image-161057" height="195" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-operating-characteristics-induction-motors-q8b.png" width="300"/></a> | |
| 8. |
For a three phase induction motor, maximum torque is double the full load torque and starting torque is 1.6 times the full load torque. To get a full load slip of 5%, percentage reduction in the rotor resistance should be? |
| A. | 62.7% |
| B. | 75% |
| C. | 60% |
| D. | 35% |
| Answer» B. 75% | |
| 9. |
A 10 kW, 400 V, 3-phase, 4-pole, 50 Hz induction motor develops the rated output at rated voltage with its slip rings shorted. The maximum torque is twice the full load torque occurs at the slip of 10% with zero external resistance in the rotor circuit. An external resistance is now tripled in the rotor circuit. Then the stator current will _________ |
| A. | remain constant |
| B. | increase |
| C. | decrease |
| D. | any of the mentioned |
| Answer» B. increase | |
| 10. |
A 10 kW, 400 V, 3-phase, 4-pole, 50 Hz induction motor develops the rated output at rated voltage with its slip rings shorted. The maximum torque is twice the full load torque occurs at the slip of 10% with zero external resistance in the rotor circuit. An external resistance is now tripled in the rotor circuit. Then the slip at which maximum torque occur for the same load torque is? |
| A. | 0.3 |
| B. | 0.268 |
| C. | 0.03 |
| D. | 3 |
| Answer» B. 0.268 | |
| 11. |
A 10 kW, 400 V, 3-phase, 4-pole, 50 Hz induction motor develops the rated output at rated voltage with its slip rings shorted. The maximum torque is twice the full load torque occurs at the slip of 10% with zero external resistance in the rotor circuit. The speed at the full load torque will be? |
| A. | 1460 rpm |
| B. | 1400 rpm |
| C. | 1360 rpm |
| D. | 1470 rpm |
| Answer» B. 1400 rpm | |
| 12. |
A 10 kW, 400 V, 3-phase, 4-pole, 50 Hz induction motor develops the rated output at rated voltage with its slip rings shorted. The maximum torque equal to twice the full load torque occurs at the slip of 10% with zero external resistance in the rotor circuit. The slip at the full load torque will be? |
| A. | 2.7% |
| B. | 5% |
| C. | 3.7% |
| D. | 10% |
| Answer» B. 5% | |