Test: Power Electronics - 4 - Electrical Engineering (EE) MCQ

A single phase half wave rectifier circuit has a free wheeling diode. The free wheeling diode will conduct only if

McMurray Bedford full bridge inverter uses

Which converter is used in HVDC transmission?

Assertion (A): The turn on time of SCR is about 1 to 4 ms.

Reason (R): The turn off time of SCR is about 10 to 300 ms.

An n pulse rectifier is fed by a source having an inductance L. If load current is I₀, the voltage drop due to overlap is

Which chopper circuit operates in all the 4 quadrants?

A single phase cycloconverter feeds a resistance heating load. The heating power is provided by

A 3 phase fully controlled bridge converter is fed by a 3 phase system having phase voltage v = V_m sin ωt. The firing angle is a. The dc output voltage is

Which of these commutation methods uses an external pulse for commutation?

In a single phase full wave regulator feeding an R-L load, the power factor angle of load is θ. The range of control of firing angle a is

A separately excited dc motor is run from a dc source through a chopper. At 600 rpm and rated torque, the duty cycle of chopper is 0.8. At 600 rpm and half the rated torque, the duty cycle is likely to be

A relaxation oscillator uses

In a 3 phase bridge inverter with 180º mode of operation the numbers of thyristors conducting at one time are

A single phase full converter can operate in

In a 3 phase semiconverter, the freewheeling diode comes into operation only if firing angle

In the circuit of figure, the load current when thyristor is off

A full bridge inverter is fed by a battery of 30 V. The rms value of output voltage is

In brushless excitation system of modern alternators, the main exciter is

The two-transistor model of a thyristor consists of two transistors :

In a thyristor, the forward breakover voltage

The gate lead, in a thyristor is welded to :

In a 3 phase full converter, the firing angle is less than 60º. The instantaneous output voltage