Operational Amplifier and Its Applications MCQs

Question 1

A Hartley oscillator is used for generating

Accepted Answer

radio-frequency oscillation

Answer

very low frequency oscillation

Answer

microwave oscillation

Answer

audio-frequency oscillation

Question 2

A Colpitts oscillator uses

Accepted Answer

tapped capacitance

Answer

tapped coil

Answer

inductive feedback

Answer

no tuned LC circuit

Question 3

In RC phase-shift oscillator circuits.

Accepted Answer

pure sine wave output is possible

Answer

there is no need for feedback

Answer

feedback factor is less than unity

Question 4

Wien bridge oscillator is most often used whenever.

Accepted Answer

wide range of high purity sine waves is to be generated

Answer

high feedback ratio is needed

Answer

square output waves are required

Answer

extremely high resonant frequencies are required

Question 5

A CE amplifier can be converted into oscillator by

Accepted Answer

phase shifting the output by 1800 and feedingothis phase-shifted output to the input.

Answer

providing adequate positive feedback

Answer

using only a series tuned circuit as a load on the amplifier

Answer

using a negative resistance device as a load on the amplifier

Question 6

The primary advantage of a crystal oscillator is that

Accepted Answer

its frequency of oscillation remains almost constant

Answer

it can oscillate at any frequency

Answer

it gives a high output voltage

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it operates on a very low dc supply voltage

Question 7

Non-sinusoidal waveforms

Accepted Answer

are departures from sine waveform

Answer

have low mark-to-space ratio

Answer

are much easier to generate

Answer

are unfit for digital operation

Question 8

A relaxation oscillator is one which

Accepted Answer

produces non-sinusoidal output

Answer

has two stable states

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relaxes indefmitely

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oscillates continuously

Question 9

A square pulse has a mark-to-space ratio of

Accepted Answer

1 : 1

Answer

1 : 2

Answer

2 : 1

Answer

1 : 4