MCQOPTIONS
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MCQOPTIONS
This section includes 11 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. |
780 V, 97 A, 1360 rpm separately excited dc motor with armature resistance (Ra) equal to 9 ohms. Calculate back emf developed in the motor when it operates on one-fourth of the full load. (Assume rotational losses are neglected) |
| A. | 564.75 V |
| B. | 561.75 V |
| C. | 562.45 V |
| D. | 565.12 V |
| Answer» C. 562.45 V | |
| 2. |
Calculate the power developed by a motor using the given data: Eb= 48 V and I= 86 A (Assume rotational losses are neglected.) |
| A. | 4128 W |
| B. | 4150 W |
| C. | 4140 W |
| D. | 4170 W |
| Answer» B. 4150 W | |
| 3. |
Calculate the radius of the circular ring having a moment of inertia 59 kgm2 and mass of 69 kg. |
| A. | .924 m |
| B. | .928 m |
| C. | .934 m |
| D. | .944 m |
| Answer» B. .928 m | |
| 4. |
The slope of the V-I curve is 31 . Calculate the value of resistance. Assume the relationship between voltage and current is a straight line. |
| A. | 0.600 |
| B. | 0.607 |
| C. | 0.543 |
| D. | 0.648 |
| Answer» B. 0.607 | |
| 5. |
Calculate the value of the frequency if the time period of the signal is 99 sec. |
| A. | 0.08 Hz |
| B. | 0.02 Hz |
| C. | 0.01 Hz |
| D. | 0.04 Hz |
| Answer» D. 0.04 Hz | |
| 6. |
340 V, 45 A, 1400 rpm DC separately excited motor having a resistance of .7 ohm excited by an external dc voltage source of 90 V. Calculate the torque developed by the motor on full load. |
| A. | 94.73 N-m |
| B. | 94.52 N-m |
| C. | 93.37 N-m |
| D. | 94.42 N-m |
| Answer» B. 94.52 N-m | |
| 7. |
Calculate the value of the angular acceleration of the motor using the given data: J = 81 kg-m2, load torque = 74 N-m, motor torque = 89 N-m. |
| A. | .195 rad/s<sup>2</sup> |
| B. | .182 rad/s<sup>2</sup> |
| C. | .183 rad/s<sup>2</sup> |
| D. | .185 rad/s<sup>2</sup> |
| Answer» E. | |
| 8. |
Calculate the moment of inertia of the hollow cylinder having a mass of 78 kg and radius of 49 cm. |
| A. | 9.363 kgm<sup>2</sup> |
| B. | 9.265 kgm<sup>2</sup> |
| C. | 9.787 kgm<sup>2</sup> |
| D. | 9.568 kgm<sup>2</sup> |
| Answer» B. 9.265 kgm<sup>2</sup> | |
| 9. |
The unit of Magnetic flux density is Tesla. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 10. |
The generated e.m.f from 45-pole armature having 400 turns driven at 70 rev/sec having flux per pole as 90 mWb, with 17 parallel paths is ___________ |
| A. | 13341.17 V |
| B. | 12370.14 V |
| C. | 14700.89 V |
| D. | 15690.54 V |
| Answer» B. 12370.14 V | |
| 11. |
Turn-on and turn-off times of transistor depend on _________ |
| A. | Static Characteristic |
| B. | Junction Capacitance |
| C. | Current Gain |
| D. | Voltage Gain |
| Answer» C. Current Gain | |