MCQOPTIONS
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MCQOPTIONS
This section includes 9 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. |
The load commutated chopper circuit consists of |
| A. | two thyristors and one commutating capacitor |
| B. | four thyristors and one commutating capacitor |
| C. | two thyristors and two commutating capacitors |
| D. | four thyristors and two commutating capacitors |
| Answer» C. two thyristors and two commutating capacitors | |
| 2. |
A voltage commutated chopper has the following parameters:Vs = 220 V. Commutation circuit: L = 20 μH and C = 50 μF.Find the turn-off time for the main SCR with a constant load current of 80 A and Ton = 800 μsecs. |
| A. | 137.5 μs |
| B. | 1075 μs |
| C. | 49.67 μs |
| D. | 200 μs |
| Answer» B. 1075 μs | |
| 3. |
A voltage commutated chopper has the following parameters:Vs = 220 V. Commutation circuit: L = 20 μH and C = 50 μF.Find the effective on period for a constant load current of 80 A and Ton = 800 μsecs. |
| A. | 1.075 μs |
| B. | 10.75 ms |
| C. | 1075 μs |
| D. | 1.075 sec |
| Answer» D. 1.075 sec | |
| 4. |
A current commutated chopper is fed from a source of 230 V. Its commutating components are L = 20 μH and C = 50 μF. Find the value of peak commutating current. |
| A. | 233 A |
| B. | 59 A |
| C. | 363 A |
| D. | 198 A |
| Answer» D. 198 A | |
| 5. |
In current commutated copper circuit |
| A. | the capacitor cannot charge on no load |
| B. | the auxiliary thyristor is turned on automatically |
| C. | the auxiliary thyristor is naturally commutated |
| D. | the commutation is not reliable |
| Answer» D. the commutation is not reliable | |
| 6. |
In the below given circuit, at the instant T1 the main SCR is triggered, the voltage across the load terminal is |
| A. | Vs |
| B. | 0 |
| C. | 2Vs |
| D. | Vs + Ldi/dt |
| Answer» B. 0 | |
| 7. |
A voltage commutated chopper feeds power to an electric car (battery-powered). The battery voltage is 60 V. Starting current is 60 A and the SCR turn-off time is 20 μs. Calculate the value of inductance (L) required for the commutating circuit. |
| A. | 400 μH |
| B. | 40 nH |
| C. | 40 μH |
| D. | . The battery voltage is 60 V. Starting current is 60 A and the SCR turn-off time is 20 μs. Calculate the value of inductance (L) required for the commutating circuit.a) 400 μHb) 40 nHc) 40 μHd) 0.4 mH |
| Answer» D. . The battery voltage is 60 V. Starting current is 60 A and the SCR turn-off time is 20 μs. Calculate the value of inductance (L) required for the commutating circuit.a) 400 μHb) 40 nHc) 40 μHd) 0.4 mH | |
| 8. |
A voltage commutated chopper feeds power to an electric car (battery-powered). The battery voltage is 60 V. The SCR turn-off time is 20 μs. Calculate the value of capacitor (C) required for the commutating circuit. |
| A. | 400 μF |
| B. | 40 nF |
| C. | 40 μF |
| D. | . The battery voltage is 60 V. The SCR turn-off time is 20 μs. Calculate the value of capacitor (C) required for the commutating circuit.a) 400 μFb) 40 nFc) 40 μFd) 0.4 mF |
| Answer» D. . The battery voltage is 60 V. The SCR turn-off time is 20 μs. Calculate the value of capacitor (C) required for the commutating circuit.a) 400 μFb) 40 nFc) 40 μFd) 0.4 mF | |
| 9. |
For the below given voltage commutation circuit, find the peak value of voltage across the freewheeling diode FD. |
| A. | Vs |
| B. | 0 |
| C. | 2Vs |
| D. | Vs + Ldi/dt |
| Answer» D. Vs + Ldi/dt | |