Q. The duty cycle of a step down chopper is

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Q. A rectifier is fed by a transformer. The rms voltage and current at secondary of transformer are Vs and Is. Output dc power is Vdc Idc and output ac power is (Vrms ) (Irms), Transformer utilisation factor TUF is

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Q. If Ar and Ac are the amplitudes of reference and control signals, the modulation index M is

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Q. For a single phase half wave converter feeding a resistive load, the firing angle a. The waveshape in below figure is for

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Q. A single phase fully controlled bridge converter is feeding an RLE load. Input voltage is Vm sin ωt and firing angle is α. If average current is I₀, then

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Q. Which of the following is not between F2 layer and D layer?

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Q. A cycloconverter can be

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Q. In a 3 phase fully controlled converter the firing frequency is

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Q. Two thyristor of same rating and same specifications

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Q. The amount of dielectric heating is inversely proportional to frequency.

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Q. A semiconverter feeding an RLE load operates in

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Q. The phenomenon of overlap in converter operation due to

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Q. A thyristor has a maximum allowable junction temperature of 120°C and the ambient temperature is 40°C. If thermal resistance is 1.6° C/W, the maximum allowable internal power dissipation is

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Q. For a 12 pulse operation, the two 6 pulse units are fed by

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Q. In a single phase full wave converter (M - 2 connection) feeding a highly inductive load, the firing angle for each thyristor is a in the respective half cycle. The period of conduction of each thyristor is

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Q. If Vdc1 is the dc output voltage in half wave controlled rectifier circuit feeding resistive load and Vdc2 is the dc output voltage in full wave controlled rectifier circuit (M - 2 connection) feeding resistive load, then

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Q. A semi converter operates in two quadrants.

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Q. Assertion (A): An ideal rectifier should have unity harmonic factor

Reason (R): An ideal rectifier should have unity displacement factor.

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Q. A single phase half wave rectifier is feeding a resistive load. When α = 0, dc output voltage is 127 V. When α = 30°, the dc output voltage will be about

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Q. A two winding transformer is feeding a single phase half wave rectifier circuit. The load is purely resistive. The rms value of transformer secondary current is Is and rms value of load current in Irms. Then

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