Objective Electronics Questions – Electrical Engineering (Page 18)

#341📘 reviewer_appMedium

When the gain is 20 without feedback and 12 with negative feedback, feedback factor is

A0.033

B3/5

C5/3

D1/5

#342📘 reviewer_appEasy

The input impedance of which amplifier depends strongly on load resistance?

ACE

BCC

CCB

DCD

#343📘 reviewer_appEasy

What capacitors are used in transistor amplifiers?

Apaper

Belectrolytic

Cmica

Dmylar

#344📘 reviewer_appEasy

An important limitation of crystal oscillator is

Aits low output

Bits high Q

Cless availability of quartz crystal

Dits high output

#345📘 reviewer_appEasy

What type of feedback is used in Wien bridge oscillator?

A+

B-

Cboth + and -

Deither + or -

#346📘 reviewer_appEasy

Which of the following below is not a description of the two-stage amplifiers

Athe input resistance is equal to the input resistance of the first stage unless feedback is applied

Bits output resistance is equal to the output resistance of the final stage unless feedback is applied

Cits noise level is equal to the accumulated noise of the two stages, either by multiplying the noise voltage amplitudes together or by adding the noise decibel levels together

Dthe output resistance is equal to the output resistance of the first stage unless feedback is applied

#347📘 reviewer_appEasy

What is the most costly coupling?

ARC coupling

Bdirect

Ctransformer

Dinductive

#348📘 reviewer_appEasy

When the output of an amplifier is 10 V and 100 mV from the output is fed back to the input, feedback factor is

A10

B0.1

C0.01

D0.15

#349📘 reviewer_appEasy

What is the piezoelectric effect in a crystal?

Avoltage is developed because of mechanical stress

Bchange in resistance because of temperature

Cchange of frequency because of temperature

Dcurrent is developed due to force applied

#350📘 reviewer_appMedium

The input resistance of a common emitter amplifier is affected by

ARe, re, and ß

BRc and re

Cß and re

Da and re

#351📘 reviewer_appEasy

What is the typical Q of a crystal?

A100

B50

C1000

Dmore than 10,000

#352📘 reviewer_appEasy

What is the axis that connects the corners of a crystal?

AX

Bmechanical

CY

DZ

#353📘 reviewer_appEasy

_____ is usually employed at the output stage of an amplifier.

Aclass A power amplifier

Bpush-pull amplifier

Cpre-amplifier

Ddifferential amplifier

#354📘 reviewer_appEasy

Why is it that the size of a power transistor is made considerably large?

Ato provide easy handling

Bto dissipate more heat

Cto simplify construction

Dto facilitate connections

#355📘 reviewer_appEasy

When crystal frequency increases with temperature, it has _____ temperature co-efficient.

A+

B-

C0

Dinfinite

#356📘 reviewer_appMedium

What is the purpose of the bypass capacitor in a common-emitter amplifier?

Ait increases voltage gain

Bit decreases voltage gain

Cit provides ac grounding

Dno effect in the circuit

#357📘 reviewer_appEasy

An emitter follower is equivalent to

Acommon emitter amplifier

Bcommon collector amplifier

Ccommon base amplifier

Dhybrid connection

#358📘 reviewer_appEasy

The crystal oscillator frequency is very stable due to _____ of the crystal.

Arigidity

Bductility

Chigh Q

Dlow Q

#359📘 reviewer_appMedium

The bandwidth of an amplifier ______ when negative feedback is applied.

Adecreases

Bremains unchanged

Cbecomes infinite

Dincreases

#360📘 reviewer_appMedium

The term 1 + Aß in the expression for gain with negative feedback is known as

Again factor

Bsacrifice factor

Cfeedback factor

Dquality factor

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