Q. Assertion (A): An ac regulator uses natural commutation

Reason (R): An ac regulator can be used for static on load tap changing of transformer.

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Q. When a UJT is used as a relaxation oscillator the current should be

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Q. In auxiliary commutated chopper, the charging and discharging time of capacitor

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Q. Which chopper circuit uses saturable reactor?

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Q. A single phase full bridge inverter for R-L loads needs

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Q. In the basic series inverter circuit, the source current has

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Q. Thyristors connected in series need static and dynamic stabilizing circuits.

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Q. In a controlled rectifier a freewheeling diode is necessary if the load is

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Q. For an illumination control circuit it is advisable to use a matched TRIAC-DIAC pair.

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Q. In a series inverter

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Q. A NAND gate has 3 inputs and one output. The number of thyristors required for this gate are

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Q. Which of these devices is used in relaxation oscillator?

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Q. In a single phase semiconverter feeding a highly inductive load, the load current is

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Q. Two thyristors of the same rating and specifications

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Q. A 3 phase induction motor is controlled by voltage and frequency control such that the ratio V/f is constant. At 50 Hz, the starting torque is 100 N-m. At 25 Hz, the starting torque

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Q. In a three phase to single phase full wave bridge cycloconverter, the number of thyristors is

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Q. In a cycloconverter it is possible to vary

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Q. Lead mounting for SCR is used for

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Q. A load commutated chopper circuit has

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Q. Assertion (A): The output voltage of an inverter can be controlled by PWM technique

Reason (R): In a current source inverter the input current is constant.

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