MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Power Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A single-phase voltage controller, using one SCR in anti parallel with a diode, feeds a load R and Vs = 230 V. For a firing angel of 90° for the SCR, the PMMC voltage connected across R would read |
| A. | 0 |
| B. | 51.8 V |
| C. | –51.8 V |
| D. | –36.82 V |
| Answer» D. –36.82 V | |
| 2. |
High frequency gating uses a |
| A. | train of pulses |
| B. | continuous gating block |
| C. | carrier signal |
| D. | none of the above |
| Answer» B. continuous gating block | |
| 3. |
In continues gating |
| A. | overlap angle is very high |
| B. | SCR is heated up |
| C. | size of the pulse transformer is small |
| D. | commutation cannot be achieved effectively |
| Answer» C. size of the pulse transformer is small | |
| 4. |
Pulse gating is suitable for |
| A. | R loads only |
| B. | R and RL loads |
| C. | RL loads only |
| D. | all types of loads |
| Answer» B. R and RL loads | |
| 5. |
A single phase voltage controller has input of 230 V and a load of 15 Ω resistive. For 6 cycles on and 4 cycles off, determine the average value of SCR current. |
| A. | 21.68 A |
| B. | 200 mA |
| C. | 4.14 A |
| D. | 2.07 A |
| Answer» D. 2.07 A | |
| 6. |
A single phase voltage controller has input of 230 V and a load of 15 Ω resistive. For 6 cycles on and 4 cycles off, determine the power delivered to the load. |
| A. | 2.1 W |
| B. | 2.1 kW |
| C. | 516 W |
| D. | 5.16 kW |
| Answer» C. 516 W | |
| 7. |
A single phase voltage controller has input of 230 V and a load of 15 Ω resistive. For 6 cycles on and 4 cycles off, determine the input pf. |
| A. | 0.6 |
| B. | 0.7746 |
| C. | 0.855 |
| D. | 0.236 |
| Answer» C. 0.855 | |
| 8. |
A single phase voltage controller has input of 230 V and a load of 15 Ω resistive. For 6 cycles on and 4 cycles off, determine the rms output voltage. |
| A. | 189 V |
| B. | 260 V |
| C. | 156 V |
| D. | 178 V |
| Answer» E. | |
| 9. |
The below given circuit has Vs = 230V and R = 20 Ω. Find the value of the average output load current at the R load for a firing angle of 45°. |
| A. | – 0.7585 |
| B. | 0.7585 |
| C. | -0.6396 |
| D. | -0.5 |
| Answer» B. 0.7585 | |
| 10. |
The below given circuit has Vs = 230V and R = 20 Ω. Find the value of the average output voltage at the R load for a firing angle of 45°. |
| A. | 224 V |
| B. | -15.17 V |
| C. | 15.17 V |
| D. | –224 V |
| Answer» C. 15.17 V | |