Power Electronics A string of n parallel SCRs is operated at 72 KA, the rating of each SCR is 1 KA. If derating factor of the string is 0.1. Then calculate the value of n 90. 60. 70. 80. 90. 60. 70. 80. ANSWER DOWNLOAD EXAMIANS APP
Power Electronics When a UJT is turned ON, the resistance between emitter terminal and lower base terminal ___________ None of these Is increased Is decreased Remains the same None of these Is increased Is decreased Remains the same ANSWER DOWNLOAD EXAMIANS APP
Power Electronics Typical range of thyristor turn OFF time is 3 - 100 µs. 3 - 50 µs. 3 - 10 µs. 3 - 500 µs. 3 - 100 µs. 3 - 50 µs. 3 - 10 µs. 3 - 500 µs. ANSWER DOWNLOAD EXAMIANS APP
Power Electronics What is used to protect the SCR from over current ? Snubber circuit. CB and fuse. Heat sink. Voltage clamping device. Snubber circuit. CB and fuse. Heat sink. Voltage clamping device. ANSWER DOWNLOAD EXAMIANS APP
Power Electronics Compared to transistor, ______________ have lower on state conduction losses and higher power handling capability TRIACs. Semi conductor diodes. MOSFETs. Thyristor. TRIACs. Semi conductor diodes. MOSFETs. Thyristor. ANSWER DOWNLOAD EXAMIANS APP
Power Electronics When a large surge current of very short duration flows through a thyristor then which one of the following device will operate to protect the thyristor ? CB. Voltage clamping device. Snubber circuit. Fast acting current limiting device (FACL fuse). CB. Voltage clamping device. Snubber circuit. Fast acting current limiting device (FACL fuse). ANSWER DOWNLOAD EXAMIANS APP
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