Q. HVDC systems are preferable for only long distances.

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Q. Surge current rating of an SCR is

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Q. Which of the following devices has metal-silicon junction?

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Q. In a series inverter

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Q. When a power diode is conducting, the voltage drop across it is about

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Q. In thermal ohm's law, temperature and power loss are analogous to

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Q. A string of series connected thyristors needs equalising circuit to

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Q. A surge voltage

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Q. The minimum gate current which can turn on SCR is called :

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Q. A thyristor circuit is feeding an R-L load. The turn on time can be reduced by

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Q. A single phase semiconverter is supplying RLE load and has a freewheeling diode across the load. The firing angle is α. The freewheeling diode conducts for

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Q. In a single phase full wave regulator feeding a resistive load, the average current over one full cycle

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Q. The total number of leads in MOS controlled thyristor is

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Q. Assertion (A): Chopper always requires forced commutation

Reason (R): Morgan chopper uses a saturable reactor.

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Q. In a power diode the reverse recovery time is the time from the instant the forward current is zero to the instant when reverse recovery current has decayed to

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Q. Assertion (A): McMurray Bredford half bridge inverter uses complementary commutation

Reason (R): Three phase inverter can have two modes of operation.

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Q. In a single phase full wave ac regulator feeding R-L load, the gate pulses

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Q. In a semi converter feeding a resistive load,

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Q. In a single phase semi-converter the number of thyristors is

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Q. A dc chopper is feeding an RLE load. The current can become discontinuous if

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