Power Electronics Questions

• As compared to a p-n junction diode
• Which of the following is correct for a BJT?
• Thyristors can be used for control of
• Assertion (A): A class C chopper can operate in first and second quadrants Reason (R): A class B chopper operates only in second quadrant.
• If Ar and Ac are the amplitudes of reference and control signals, the modulation index M is
• A single phase dual converter consists of
• In a single phase half wave ac regulator feeding a resistive load, the rms load current
• In a 3 phase bridge inverter, the gating signals for the three phases have a phase difference of
• In a single phase cycloconverter with centre tapped transformer
• In a full bridge circuit supplying an RLC under damped circuit
• The method of triggering SCS is
• A fully controlled bridge converter is feeding an RLE load. The load current is I0. The input voltage is Vm sin ωt. The KVL equation to find firing angle a is
• The condition for underdamped oscillations in a series RLC circuit is
• When thyristors are connected in parallel, the current distribution may become non-uniform due to
• In a bridge inverter with single pulse width modulation
• For a single phase half wave converter feeding a resistive load, the firing angle a. The waveshape in below figure is for
• The number of layers in a Shockley diode are
• A LASCR has
• Assertion (A): Thyristors can be used in controlled heating, excitation systems of alternators, speed control of motors and HVDC Reason (R): A static var system using thyristors is very commonly used in high voltage ac systems.
• 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