MCQOPTIONS
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MCQOPTIONS
This section includes 11 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. |
Starting torque induced in a three phase induction motor in a direction of rotating magnetic field depends on _________ |
| A. | number of poles squared |
| B. | inverse of number of poles |
| C. | number of poles |
| D. | number of number poles cubic |
| Answer» B. inverse of number of poles | |
| 2. |
The external resistance can be inserted in rotor circuit of _________ |
| A. | wound rotor induction motor |
| B. | slip ring induction motor |
| C. | wound rotor as slip ring induction motor |
| D. | neither of motors |
| Answer» B. slip ring induction motor | |
| 3. |
For a 6-pole three phase squirrel cage induction motor has flux density wave of four poless, then the rotor induced poles will be? |
| A. | 4 |
| B. | 6 |
| C. | 2 |
| D. | 10 |
| Answer» B. 6 | |
| 4. |
In an induction motor, the stator is also known as _________ and the rotor as __________ |
| A. | field winding, armature winding |
| B. | armature winding, field winding |
| C. | armature winding, compensating winding |
| D. | armature winding, interpole winding |
| Answer» B. armature winding, field winding | |
| 5. |
For a slip ring induction motor having leakage impedance of (1+j), the maximum generated emf would be attained at _________ |
| A. | 135 |
| B. | 45 |
| C. | -45 |
| D. | 0 |
| Answer» B. 45 | |
| 6. |
For the three phase induction motor having leakage impedance, the maximum generated emf would be attained at an angle of having a purely resistive load is? |
| A. | 90 + |
| B. | |
| C. | 90 |
| D. | - |
| Answer» B. | |
| 7. |
In a three phase induction motor of rotor impedance as (0.2+j0.2), rotor current in each phase lags behind the generated emf in that phase to rotor by a power factor angle of _________ |
| A. | 45 |
| B. | 135 |
| C. | 90 |
| D. | 0 |
| Answer» B. 135 | |
| 8. |
In a three phase induction motor, rotor current in each phase lags behind the generated emf in that phase to rotor by a power factor angle of _________ |
| A. | atan(r2/x2) |
| B. | atan(x2/r2) |
| C. | atan(x1/r1) |
| D. | atan(r1/x1) |
| Answer» C. atan(x1/r1) | |
| 9. |
Mark the most appropriate phasor for the induction machine operation as motor. |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3a.png"><img alt="Phasor for the induction machine operation as motor - option a" class="alignnone size-full wp-image-160997" height="147" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3a.png" width="152"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3b.png"><img alt="Phasor for the induction machine operation as motor - option b" class="alignnone size-full wp-image-160998" height="197" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3b.png" width="168"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3c.png"><img alt="Phasor for the induction machine operation as motor - option c" class="alignnone size-full wp-image-160999" height="157" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3c.png" width="167"/></a> |
| D. | none of the mentioned |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3b.png"><img alt="Phasor for the induction machine operation as motor - option b" class="alignnone size-full wp-image-160998" height="197" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q3b.png" width="168"/></a> | |
| 10. |
Mark the correct waveform for the emf produced in an induction motor and the resultant flux density wave for a resistive load. |
| A. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2a.png"><img alt="Waveform for resultant flux density wave for a resistive load - option a" class="alignnone size-full wp-image-160993" height="164" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2a.png" width="300"/></a> |
| B. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2b.png"><img alt="Waveform for resultant flux density wave for a resistive load - option b" class="alignnone size-full wp-image-160994" height="163" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2b.png" width="300"/></a> |
| C. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2c.png"><img alt="Waveform for resultant flux density wave for a resistive load - option c" class="alignnone size-full wp-image-160995" height="191" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2c.png" width="300"/></a> |
| D. | <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2d.png"><img alt="Waveform for resultant flux density wave for a resistive load - option d" class="alignnone size-full wp-image-160996" height="145" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2d.png" width="300"/></a> |
| Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2b.png"><img alt="Waveform for resultant flux density wave for a resistive load - option b" class="alignnone size-full wp-image-160994" height="163" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-campus-interviews-q2b.png" width="300"/></a> | |
| 11. |
A three phase induction motor is not self starting. |
| A. | True |
| B. | False |
| Answer» C. | |