Q. 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 α is

View solution

Q. 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

View solution

Q. A relaxation oscillator uses

View solution

Q. In a stud mounted SCR, the stud is

View solution

Q. In pulse width modulation of chopper

View solution

Q. In a full bridge inverter, the waveshape of load current depends on

View solution

Q. The characteristics of which device has peak point and valley point

View solution

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

View solution

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

View solution

Q. In a thyristor, the forward breakover voltage

View solution

Q. The gate lead, in a thyristor is welded to :

View solution

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

View solution

Q. Which converter is used in HVDC transmission?

View solution

Q. 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.

View solution

Q. Which chopper circuit operates in all the 4 quadrants?

View solution

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

View solution

Q. A voltage VBB is applied across the terminals of a UJT. The emitter voltage at peak point is

View solution

Q. A single phase bridge type cycloconverter uses eight thyristors.

View solution

Q. In the basic series inverter circuit, the source supplies load

View solution

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

View solution