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. |
The value of slip at which maximum torque occurs ________ |
| A. | R<sub>2</sub> X<sub>2</sub> |
| B. | 4R<sub>2</sub> X<sub>2</sub> |
| C. | 2R<sub>2</sub> X<sub>2</sub> |
| D. | R<sub>2</sub> 3X<sub>2</sub> |
| Answer» B. 4R<sub>2</sub> X<sub>2</sub> | |
| 2. |
Calculate the total heat dissipated in a resistor of 44 when 0 A current flows through it. |
| A. | 0 W |
| B. | 2 W |
| C. | 1.5 W |
| D. | .3 W |
| Answer» B. 2 W | |
| 3. |
Calculate the time period of the waveform v(t)=12sin(8 t+8 15)+144sin(2 t+ 6)+ 445sin( t+7 6). |
| A. | 8 sec |
| B. | 4 sec |
| C. | 7 sec |
| D. | 3 sec |
| Answer» C. 7 sec | |
| 4. |
At low values of slip, the electromagnetic torque is directly proportional to ___________ |
| A. | s |
| B. | s<sup>2</sup> |
| C. | s<sup>3</sup> |
| D. | s<sup>4</sup> |
| Answer» B. s<sup>2</sup> | |
| 5. |
The power factor of a squirrel cage induction motor is ___________ |
| A. | High at light load only |
| B. | High at heavy loads only |
| C. | Low at the light and heavy loads both |
| D. | Low at rate load only |
| Answer» C. Low at the light and heavy loads both | |
| 6. |
If induction motor air gap power is 1.8 KW and gross developed power is .1 KW, then rotor ohmic loss will be _________ KW. |
| A. | 1.7 |
| B. | 2.7 |
| C. | 3.7 |
| D. | 4.7 |
| Answer» B. 2.7 | |
| 7. |
The slope of the V-I curve is 9.1 . Calculate the value of resistance. Assume the relationship between voltage and current is a straight line. |
| A. | .16 |
| B. | .26 |
| C. | .25 |
| D. | .44 |
| Answer» B. .26 | |
| 8. |
In the rotor voltage injection method, when an external voltage source is in opposite phase with the main voltage then speed will ___________ |
| A. | Increase |
| B. | Decrease |
| C. | Remain unchanged |
| D. | First increases then decrease |
| Answer» C. Remain unchanged | |
| 9. |
Calculate the average value of the sinusoidal waveform x(t)=848sin(1.65 t+2 0.68). |
| A. | 0 |
| B. | 78 V |
| C. | 15 V |
| D. | 85 V |
| Answer» B. 78 V | |
| 10. |
A 2-pole, 3-phase, ______ Hz induction motor is operating at a speed of 550 rpm. The frequency of the rotor current of the motor in Hz is 2. |
| A. | 9.98 |
| B. | 9.71 |
| C. | 9.12 |
| D. | 9.37 |
| Answer» E. | |
| 11. |
In the rotor voltage injection method, when an external voltage source is in phase with the main voltage then speed will ___________ |
| A. | Increase |
| B. | Decrease |
| C. | Remain unchanged |
| D. | First increases then decrease |
| Answer» B. Decrease | |