# Category: Power Electronics

## Delay time is defined by the interval when_______________? A. gate current increases from 90 % to 100 % of its final value
B. anode current reaches 10 % from forward leakage current
C. anode voltage drops from 100 % to 90 % of its actual value
D. all of these

## The power demand can be estimated approximately by____________? B. Mathematical method
C. Statistical method
D. Economic parameters

## What is the advantage of HRC fuses over Rewirable fuses? A. High speed operation
B. High rupturing capacity
C. No ageing effect
D. All of the above

## The curve between V and I of SCR when anode is positive w.r.t cathode and when anode is negative w.r.t cathode are known as_____________________? A. both as forward characteristics
B. both as reverse characteristics
C. former as forward characteristics and later as reverse characteristics
D. former as reverse characteristics and later as forward characteristics

## Which triggering is the most reliable____________? A. Forward voltage triggering
B. Gate triggering
C. dV / dt triggering
D. Thermal triggering

## In a 3 phase VSI out of eight valid states, the number of valid states that produce zero ac line voltages is/are_________? A. One
B. two
C. Three
D. Four

## The turn-on time of an SCR with inductive load is 20 µs. The puls train frequency is 2.5 KHz with a mark/space ratio of 1/10, then SCR will___________? A. Turn on
B. Not turn on
C. Turn on if inductance is removed
D. Turn on if pulse frequency us increased to two times

## By which one of the following we can measure the reliability of a string_____________? A. String efficient
B. Reliability factor
C. Factor of safety
D. Derating factor

## The output power of the cascaded amplifier / attenuator system can be determined using___________? A. Actual gain of amplifier
B. Actual gain of amplifier and attenuator
C. Gain in dB of amplifier and attenuator
D. Actual gain of attenuator

## The most suited gate pulses given to the AC regulator with R – L load can be in the form of____________? A. Continuous signal
B. Large isolating pulse transformer
C. A train of pulses
D. None of these