Q. A dc series motor is coupled to a load whose torque is proportional to speed. It is fed by a single phase ac supply through a full converter. When speed is 500 rpm, firing angle is 45°. It is desired to raise the speed. It will be necessary to

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Q. In Jone chopper, the commutating element

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Q. A LASCR has

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Q. In a modified series inverter

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Q. Assertion (A): Light triggering is very suitable for HVDC transmission.

Reason (R): Light triggering has the advantage of complete electrical isolation of gate circuit.

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Q. Class A and class B chopper

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Q. To turn off an SCR, it is necessary to reduce its current to less than :

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Q. When a single phase dual converter is operating in circulating current mode

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Q. In a 3 phase bridge inverter, the gating signals for the three phases have a phase difference of

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Q. The total number of leads in SCR, DIAC and TRIAC respectively are

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Q. A single phase semiconverter is feeding a highly inductive load and has a freewheeling diode across the load. The waveshape of input current is

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Q. In a semi converter feeding a resistive load

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Q. In an n stage high frequency series inverter having a time period T, each stage is active for a time interval of

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Q. In a 3 phase semiconverter, the output voltage becomes discontinuous for

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Q. In integral cycle control of ac regulator, the input power factor is equal to

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Q. McMurrary full bridge inverter uses

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Q. A fully controlled bridge converter feeds a highly inductive load such that the load current can be assumed to be constant. The wave shape of input current is

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Q. A static excitation system uses

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Q. The application of gate signal decreases the break over voltage of on SCR.

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Q. The power factor at the input terminals of a cyclo- converter is generally

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