In BJT, the forward biased base emitter junction inject holes from base to emitter, the holes_______?

A. Do not contribute to the collector current
B. Result in net current flow component into the base
C. Contribute to the collector current
D. Only (a) and (b)

In BJT, switching losses occurs___________?

A. Only at turn – on
B. Only at turn – off
C. Both at turn on and off
D. None of these

In radiative coupling, the emitter radiation field_____________?

A. Decays as 1 / r, where r is the separation distance between the emitter and the receptor
B. Decays as r, where r is the separation distance between the emitter and the receptor
C. Decays as 1 / 2 r, where r is the separation distance between the emitter and the receptor
D. Decays as 2r, where r is the separation distance between the emitter and the receptor

Choppers is a_______________?

A. Ac – dc converters
B. Ac – ac converters
C. Dc – ac converters
D. Dc – dc converters

The effects of EMI can be reduced by____________?

A. Suppressing emissions
B. Reducing the efficiency of the coupling path
C. Reducing the susceptibility of the receptor
D. All of these

The average value of the output voltage in a step – down dc chopper is given by__________?

A. V 0 = v s
B. V 0 = d v s
C. V 0 = v s / d
D. V 0 = v s / ( 1 – d )

Between the incoming and outgoing devices in voltage commutation

A. Large overlapping takes place
B. Small overlapping operation
C. No overlapping operation
D. None of these

The control method used for PWM dc – dc converter is______________?

A. Voltage mode control
B. Current mode control
C. Hysteric control
D. All of these

During the commutation period in 3 phase converter, overlap time is_____________?

A. Dependent on the load current
B. Dependent on the voltage
C. Dependent on both the load current and load voltage behind the short circuit current
D. Independent on both the load current and load voltage

The main objective of static power converters is to____________?

A. Obtain an dc output waveform from a dc power supply
B. Obtain an ac output waveform from a dc power supply
C. Obtain an dc output waveform from a dc power supply
D. Obtain an ac output waveform from a ac power suppl