MCQOPTIONS
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MCQOPTIONS
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Electric Drives knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A 2-pole lap wound generator with 44 armature conductors and a flux per pole of .07 Wb has an armature current of 80 A. The developed torque is _________ |
| A. | 39.7 N-m |
| B. | 39.2 N-m |
| C. | 38.4 N-m |
| D. | 37.2 N-m |
| Answer» C. 38.4 N-m | |
| 2. |
The slope of the V-I curve is 13 . Calculate the value of resistance. Assume the relationship between voltage and current is a straight line. |
| A. | .2544 |
| B. | .7771 |
| C. | .2308 |
| D. | .5788 |
| Answer» D. .5788 | |
| 3. |
Calculate the active power in a 1 resistor with 2 A current flowing through it. |
| A. | 2 W |
| B. | 4 W |
| C. | 7 W |
| D. | 1 W |
| Answer» C. 7 W | |
| 4. |
Which of the following core has linear characteristics? |
| A. | Air core |
| B. | Steel core |
| C. | CRGO core |
| D. | Iron core |
| Answer» B. Steel core | |
| 5. |
A 3-phase induction motor runs at almost 1100 rpm at no load and 640 rpm at full load when supplied with power from a 50 Hz, 3-phase supply. What is the corresponding speed of the rotor field with respect to the rotor? |
| A. | 430 revolution per minute |
| B. | 440 revolution per minute |
| C. | 460 revolution per minute |
| D. | 450 revolution per minute |
| Answer» D. 450 revolution per minute | |
| 6. |
Which one of the following methods would give a higher than the actual value of regulation of the alternator. |
| A. | ZPF method |
| B. | MMF method |
| C. | EMF method |
| D. | ASA method |
| Answer» D. ASA method | |
| 7. |
The slope of the V-I curve is 45 . Calculate the value of resistance. Assume the relationship between voltage and current is a straight line. |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 1 |
| Answer» E. | |
| 8. |
The frame of a synchronous motor is made of _________ |
| A. | Aluminum |
| B. | Silicon steel |
| C. | Cast iron |
| D. | Stainless steel |
| Answer» D. Stainless steel | |
| 9. |
The power factor of a synchronous motor __________ |
| A. | Improves with an increase in excitation and may even become leading at high excitations |
| B. | Decreases with increase in excitation |
| C. | Is independent of its excitation |
| D. | Increase with loading for a given excitation |
| Answer» B. Decreases with increase in excitation | |
| 10. |
Calculate the moment of inertia of the thin spherical shell having a mass of 3 kg and diameter of 6 cm. |
| A. | .0178 kgm<sup>2</sup> |
| B. | .0147 kgm<sup>2</sup> |
| C. | .0398 kgm<sup>2</sup> |
| D. | .0144 kgm<sup>2</sup> |
| Answer» B. .0147 kgm<sup>2</sup> | |
| 11. |
Calculate the moment of inertia of the disc having a mass of 1 kg and radius of 1 m. |
| A. | 1 kgm<sup>2</sup> |
| B. | .5 kgm<sup>2</sup> |
| C. | 2 kgm<sup>2</sup> |
| D. | 3 kgm<sup>2</sup> |
| Answer» C. 2 kgm<sup>2</sup> | |
| 12. |
Calculate the phase angle of the sinusoidal waveform w(t)=.45sin(87 t+8 787). |
| A. | 2 39 |
| B. | 8 787 |
| C. | 5 74 |
| D. | 42 4 |
| Answer» C. 5 74 | |
| 13. |
A 2-pole, 3-phase, 50 Hz induction motor is operating at a speed of 400 rpm. The frequency of the rotor current of the motor in Hz is __________ |
| A. | 43.33 |
| B. | 42.54 |
| C. | 43.11 |
| D. | 41.47 |
| Answer» B. 42.54 | |
| 14. |
The ferrite cores are used for ____________ transformers. |
| A. | Small transformers |
| B. | Medium transformers |
| C. | Large transformers |
| D. | Medium and small transformers |
| Answer» B. Medium transformers | |