ISRO Scientist or Engineer Electrical 2018

Find the voltage drop $$(V_d)$$ across Silicon diode in the circuit below.

In the circuit given below Inductor used is ideal inductor, What is the conduction angle of diode?

A single phase full bridge converter supplies power to constant current load. If the triggering angle is $$45^\circ$$, what is the input power factor of the converter?

Input voltage $$v = 230 \sin(100 \pi t)$$ Volts is given to a converter and the current drawn by the converter is $$i = 20 \sin \left(100 \pi t - \frac{\pi}{3}\right) + 10 \sin(300 \pi t + 45^\circ) + 2 \sin \left(700 \pi t - \frac{\pi}{6}\right)$$ Amps. What is the active power drawn by the converter?

If a boost converter operates with a duty ratio D = 1 then output voltage is

In a single phase asymmetrical half controlled rectifier with firing angle ‘$$\alpha$$’ feeds a constant current load. What will be conduction angle of diodes?

In a three phase half controlled rectifier with constant current load and freewheeling diode, what is the fraction of cycle the diode conducts? Consider firing angle $$(\alpha)$$ of thyristors greater than $$60^\circ$$.

A step down chopper operates from a $$D.C.$$ voltage source $$V_s = 400 V$$ and feeds a $$DC$$ motor armature with a back emf $$E_b = 300 V$$. From the oscilloscope traces it is found that the current rises for a time $$t_r = 10$$ m sec and falls to zero over time $$t_f = 5$$ m sec and remains zero for a time of $$t_o = 6$$ m sec in every chopping cycle. Then, average $$DC$$ voltage across the freewheeling diode will be

A single phase inverter has a square wave output voltage. What is the percentage of fifth harmonic component in relation to fundamental component present in the output voltage?

In the LC circuit shown in the figure initial current through the inductor is zero, initial voltage across the capacitor is 100 V. Switch S is closed at t = 0 sec. The current through the circuit is