Electrical Engineering Mcqs Practice Test

Question 1

A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by________?

Accepted Answer

A. 2

Question 2

MOSFET can be used as a__________?

Accepted Answer

B. voltage controlled capacitor

Question 3

Which of the following amplifier circuit using junction transistor has the best gain?

Accepted Answer

B. Common emitter

Question 4

The horizontal intercept of dc load line is the same as ideal____________?

Accepted Answer

A. cut off point

Question 5

In a CB amplifier the maximum efficiency could be____________?

Accepted Answer

D. 25%

Question 6

Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in____________?

Accepted Answer

C. Both Temperature & β

Question 7

The most commonly used amplifier in sample & hold circuits is______________?

Accepted Answer

B. A unity gain inverting amplifier

Question 8

In a full-wave rectifier using two ideal diodes,Vdc & Vm are the dc & peak values of the voltage respectively across a resistive load. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier is____________?

Accepted Answer

B. Vdc = 2Vm/π, PIV=2vm

Question 9

The action of JFET in its equivalent circuit can best be represented as a_____________?

Accepted Answer

D. voltage controlled current source

Question 10

Generally, the gain of a transistor amplifier falls at high frequencies due to the___________?

Accepted Answer

A. Internal Capacitance of the device

Question 11

The current gain of a bipolar transistor drops at high frequencies because of____________?

Accepted Answer

A. Transistor capacitances

Question 12

Negative feedback in an amplifier____________?

Accepted Answer

A. Reduces gain

Question 13

Class AB operation is often used in power large signal amplifiers in order to_________?

Accepted Answer

C. overcome a crossover distortion

Question 14

An n- channel JFET has IDSS=2mA,and Vp=-4v.Its transconductance gm=in mA/V)for an applied gate to source voltage VGS=-2v is___________?

Accepted Answer

B. 0.5

Question 15

The effective channel length of a MOSFET in a saturation decreases with increase in___________?

Accepted Answer

B. Drain voltage

Question 16

A differential amplifier is invariably used in the i/p stage of all OP-amps. This is done basically to provide the OP-amps with a very high_________?

Accepted Answer

C. Slew rate

Question 17

An OPAMP has a slew rate of 5 V/μ S .The largest sine wave O/P voltage possible at a frequency of 1 MHZ is [Hint: Slew rate is defined as the max. rate of change of output voltage. Its unit is V/μS.

Accepted Answer

D. 5/2 volts

Question 18

A source follower using an FET usually has a voltage gain which is___________?

Accepted Answer

A. greater than +100

Question 19

The early effect in a bipolar junction transistor is caused by_______________?

Accepted Answer

C. large collector-base reverse bias

Question 20

In an op-amp differentiator:________________?

Accepted Answer

A. the amplitude of output is proportional to rate of change of input