Q121
Open questionAn SCR remains turned on if the anode current is more than the
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Q122
Open questionCalculate the power factor of a single-phase thyristor-controlled bridge rectifier if the firing angle is 30°.
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Q123
Open questionAn incremental model of a solid state device is one which represents the
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Q124
Open questionWhich of the following thyristors can be used for high frequency of operation?
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Q125
Open questionFor harmonic distortion reading of D2 = 0.1, D3 = 0.02 and D4 = 0.01, with I1 = 4 A and RC = 8 Ω, calculate the total harmonic distortion (THD) fundamental power component (P1), and total power (P).
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Q126
Open questionThe ON voltage and forward break over voltage of an SCR depend on the
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Q127
Open questionOnce the SCR starts conducting a forward current, its gate loses control over
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Q128
Open questionA High speed digital subsystem requires three voltages V1, V2 and V3 with 1 : 2 : 1 power ratings, respectively. The power supply is designed with the distribute power conversion scheme as shown in the following figure. What is the overall power conversion efficiency?
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Q129
Open questionDC choppers belong to the category of,
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Q130
Open questionA Triac has three terminals viz . . . . . . . .
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Q131
Open questionConsider the following statements:
The turnoff time of an SCR can be reduced by
1. Quick withdrawal of the gate voltage.
2. Reducing lifetimes by doping with gold.
3. Applying a negative voltage pulse to the gate of these statements:
The turnoff time of an SCR can be reduced by
1. Quick withdrawal of the gate voltage.
2. Reducing lifetimes by doping with gold.
3. Applying a negative voltage pulse to the gate of these statements:
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Q132
Open questionAn SCR can be brought to forward conducting state with gate circuit open when the applied voltage exceeds
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Q133
Open questionWhich of the following statements about the working of SCR is INCORRECT?
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Q134
Open questionWhich of the following components convert fixed DC to variable DC?
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Q135
Open questionIn a DIAC the breakdown voltages are related with the following equation:
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Q136
Open questionWhich one of the following statements is correct about SCR?
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Q137
Open questionTwo Thyristors of same rating and same specification
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Q138
Open questionForward voltage drop during SCR turn-on is 1.5 V this drop remains
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Q139
Open questionIdentify A and B current limiting techniques in a.c. to d.c. power supplies respectively, in the graph below.
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Q140
Open questionWhen a thyristor is negatively biased,
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