Exercise :: Power Electronics - Section 1
| 31. | In a circuit using a full wave converter (M - 2 connection) the PIV of each thyristor is 400 V. For the same output voltage and fully controlled bridge converter, PIV will be |
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Answer: Option C Explanation: In bridge connection PIV is half of that in M-2 connection. |
| 32. | A dc separately excited motor has constant field current. The armature is fed from a single phase supply through a full converter. When a = 0, speed is 500 rpm. If a = 45°, the speed is likely to be |
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Answer: Option D Explanation: Average output voltage ∝ cos a and therefore reduced to 0.707 of the value for a = 0. Speed is nearly proportional to voltage. |
| 33. | In a multiphase chopper, all choppers operate together. |
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Answer: Option B Explanation: They operate in a sequence. |
| 34. | The terminals of a power MOSFET are called |
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Answer: Option B Explanation: In a MOSFET terminals are source, gate, drain irrespective of rating. |
| 35. | Assertion (A): The surge current which an SCR can withstand is much higher than rms on state current. Reason (R): The duration of surge current is very small. |
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Answer: Option A Explanation: Since duration of surge current is small, the associated energy is small. |