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. |
SCR determines the stability of the synchronous machine. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
Calculate the value of the short circuit ratio if Voc=78 V, Isc=15 A with field current = 5 A. |
| A. | 5.2 |
| B. | 4.8 |
| C. | 3.2 |
| D. | 1.8 |
| Answer» B. 4.8 | |
| 3. |
Armature reaction is cross-magnetizing in nature due to a resistive load in the synchronous generator. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4. |
Armature reaction is purely demagnetizing in nature due to a capacitive load in the synchronous motor. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 5. |
The phase difference between voltage and current in the purely inductive coil. |
| A. | 20° |
| B. | 90° |
| C. | 40° |
| D. | 88° |
| Answer» C. 40° | |
| 6. |
Calculate the value of the duty cycle if the system is on for 1 sec and off for inf sec. |
| A. | 0 |
| B. | .89 |
| C. | .148 |
| D. | .46 |
| Answer» B. .89 | |
| 7. |
The slope of the I-V curve is 180°. Calculate the value of resistance. |
| A. | inf Ω |
| B. | .81 Ω |
| C. | 45 Ω |
| D. | 41.2 Ω |
| Answer» B. .81 Ω | |
| 8. |
Calculate the reactive power in a 725.45 Ω resistor. |
| A. | 122.1 VAR |
| B. | 261.1 VAR |
| C. | 0 VAR |
| D. | 199.7 VAR |
| Answer» D. 199.7 VAR | |
| 9. |
What is the unit of displacement? |
| A. | m/s |
| B. | m |
| C. | atm/m |
| D. | Volt |
| Answer» B. m | |
| 10. |
Calculate the reactive power in a 451.26 Ω resistor. |
| A. | 1 VAR |
| B. | .6 VAR |
| C. | 0 VAR |
| D. | .9 VAR |
| Answer» D. .9 VAR | |
| 11. |
Calculate the power factor if the power angle is 45°. |
| A. | 0.707 |
| B. | .407 |
| C. | .608 |
| D. | 1 |
| Answer» B. .407 | |
| 12. |
The unit of area is m2. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 13. |
Cylindrical pole machines are less stable than salient rotor machines. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 14. |
Calculate the minimum value of the active power in the cylindrical rotor synchronous machine? (Eb represents armature emf, Vt represents terminal voltage, δ represents rotor angle, X represents reactance) |
| A. | Eb×Vt×sinδ÷X |
| B. | 0 |
| C. | Eb2×Vt×sinδ÷X |
| D. | Eb×Vt÷X |
| E. | Eb×Vt×sinδ÷Xb) 0c) Eb2×Vt×sinδ÷Xd) Eb×Vt÷X |
| Answer» C. Eb2×Vt×sinδ÷X | |