Electrical Engineering Mcqs Practice Test

Question 1

In a load commutated DC – DC chopper, the capacitor has a_____________?

Accepted Answer

C. Symmetric trapezoidal voltage across itself

Question 2

The sum of all phase current in a star connected primary winding with no neutral connection is equal to___________?

Accepted Answer

D. Zero at all times

Question 3

In current commutated DC-DC choppers, the voltage spike appears across the load when_____________?

Accepted Answer

C. Both A. and B.

Question 4

For power output higher than 15 kW, the suitable rectifier is________________?

Accepted Answer

D. Only (b) and (c)

Question 5

In a full wave rectifier, the rectification ratio is approximately equal to____________?

Accepted Answer

C. 81%

Question 6

LISN is a device used to measure conducted emissions. LISN stands for_____________?

Accepted Answer

B. Line impedance stabilization network

Question 7

In a single phase full wave rectifier, during blocking state the pea inverse voltage of diode is______________?

Accepted Answer

B. 2 V m

Question 8

A single phase ac – dc converter is also known as____________?

Accepted Answer

A. rectifier

Question 9

The output power of the cascaded amplifier / attenuator system can be determined using___________?

Accepted Answer

B. Actual gain of amplifier and attenuator

Question 10

If the gate voltage of an SCR is removed, then the_______________?

Accepted Answer

B. anode current does not decrease at all

Question 11

Anode of an operational SCR is _______________?

Accepted Answer

A. Always positive w.r.t cathode

Question 12

An SCR is made up of silicon because?

Accepted Answer

B. silicon has small leakage current than germanium

Question 13

In a silicon controlled rectifier, the load is connected___________?

Accepted Answer

B. In series with anode

Question 14

AC power in a load can be controlled by using____________?

Accepted Answer

A. Two SCR’s in parallel opposition

Question 15

Number of PN junction in an SCR is____________?

Accepted Answer

B. Three

Question 16

The switching function of semiconductor devices can be characterized with___________?

Accepted Answer

D. Duty ratio, frequency and time delay

Question 17

IGBT stands for___________?

Accepted Answer

A. Insulated gate bipolar transistor

Question 18

Electrical power output in a d.c. generator is equal to____________?

Accepted Answer

D. Mechanical power input – iron and friction losses – copper losses

Question 19

An ideal switch is___________?

Accepted Answer

D. All of these

Question 20

In ac – dc conversion, when the switch is closed then the sum of voltages around the loop is____________?

Accepted Answer

B. Non zero