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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

What is a second-order low pass active filter?

Answer»

It is a two-stage RC filter circuit followed by an op-amp non inverting amplifier.
Discussion
2.

What is a digital to analog converter?

Answer»

A digital to analog converter is used for conversion of digital input into an analog output.
Discussion
3.

What is a zero crossing detector?

Answer»

Zero crossing detector is a circuit whose output voltage switches its state. This circuit can be used to convert sine waveform to square waveform.
Discussion
4.

What is analog to digital converter?

Answer»

An analog to digital converter is used for conversion of an analog input into a digital output.
Discussion
5.

What is an integrator?

Answer»

Integrator is a circuit whose output is proportional to intergral of its input.
Discussion
6.

What are the different kinds of packages of Op-amp?

Answer»

(i) Mono package.

(ii) Dual package.
Discussion
7.

Name any two types of digital to analog converter.

Answer»

(i) R-2R ladder network.

(ii) Binary weighted resistor.
Discussion
8.

Mention any two non-linear applications of Op-amp.

Answer»

(i) Differentiator

(ii) Integrator.
Discussion
9.

Mention some of non-linear applications of op-amps.

Answer»

Differentiator, Integrator, logarithmic amplifier.
Discussion
10.

Write any three differences between ideal and practical op-amps.

Answer»
CharacteristicsIdeal op-ampPractical op-amp.
Input impedanceInfinityfew MQ.
Output impedance0few ohm.
BandwidthInfinityfew MHZ.
Discussion
11.

List out any two characteristics of practical Op-amp.

Answer»

(i) Input impedance is few MΩ

(ii) The open-loop gain is 105.
Discussion
12.

Mention some of the linear applications of op-amp.

Answer»

Inverting amplifier, non-inverting amplifier, op-amp summing amplifier, op-amp substractor.
Discussion
13.

Mention any two linear applications of Op-amp.

Answer»

(i) Inverting amplifier

(ii) Non-inverting amplifier.
Discussion
14.

List out any two characteristics of an ideal Op-amp.

Answer»

(i) Infinite input impedance.

(ii) Infinite open loop gain.
Discussion
15.

Explain how an ideal op-amp different from a practical op-amp?

Answer»
CharacteristicsIdeal op ampPractical op-amp
open loop gain∞105
Input impedance∞Few M Ω.
Output impedance0Few ohm.
Bandwidth∞Few MHz.
CMRR∞90 dB
Discussion
16.

What are the assumptions made for ideal op-amp characteristics?

Answer»

Infinite open-loop gain, Infinite bandwidth, Infinite input impedance, Zero output impedance, infinite CMRR.
Discussion
17.

Define CMRR of an Op-amp.

Answer»

CMRR is defined as the ratio of differential mode gain to common mode gain.
Discussion
18.

What do you mean by virtual ground with respect to an Op-amp?

Answer»

Zero voltage at the inverting terminal is called virtual ground.
Discussion
19.

List parameters of an ideal op-amp and also write its values for 741 op-amp.

Answer»
CharacteristicsIdeal op ampPractical op amp
open-loop gain∞105
Input impedance∞Few M Q.
Output impedance0Few ohm.
Bandwidth∞Few MHz.
CMRR∞90 dB
Slew rate∞0.5v/ps
Input offset voltage0Few mV.
Discussion
20.

Explain virtual ground concept with respect to op-amp.

Answer»

If VA and VB are the voltages at inverting and non-inverting terminals, then open-loop gain.

A = \(\frac{V_o}{V_B-V_A}\) = ∞

∴ VB - VA = 0

(or) VA = VB

As VB = 0 (as non-inverting terminal is grounded), VA = 0.
Zero voltage at the inverting terminal is called virtual ground.
Discussion
21.

Define slew rate.

Answer»

Slew rate is the maximum rate of change of output voltage when a large input signal is given to the closed loop amplifier.
Discussion
22.

What is a first-order low pass active filter?

Answer»

It is a single-stage RC filter circuit followed by an op-amp non-inverting amplifier.
Discussion
23.

What is an Op-amp?

Answer»

OP-amp is a direct coupled high gain amplifier with large bandwidth.
Discussion
24.

Define slew rate of an op-amp.

Answer»

Slew rate of an op-amp is the maximum rate of change of output voltage when a large input signal is given to the closed-loop amplifier.
Discussion
25.

What is an active filter?

Answer»

Active filters are circuits which make use of passive components such as resistors and active components such as op-amp for the selection of band of frequencies.
Discussion
26.

What is a differential amplifier?

Answer»

Differential amplifier is the amplifier which amplifies the difference between the input signals.
Discussion
27.

What is logarithmic amplifier?

Answer»

Logarithmic amplifier is a circuit whose output is proportional to natural logarithm of the input voltage.
Discussion
28.

Name four modes of differential amplifiers.

Answer»

(i) Dual input and balanced output differential amplifier.

(ii) Single input and single output differential amplifier.

(iii) Dual input and unbalanced output differential amplifier.

(iv) Single input and balanced output differential amplifier.
Discussion
29.

Name any one application of Schmitt Trigger?

Answer»

Schmitt Trigger is used to convert any periodically varying signal into a square wave.
Discussion
30.

What is Comparator?

Answer»

Comparator compares one input of the op-amp with the other input of the op-amp.
Discussion
31.

Name any open loop application of an op – amp.

Answer»

Open loop application of an op-amp is Comparator.
Discussion
32.

What is a Schmitt trigger?

Answer»

It is a comparator which compares the varying input signal with positive feedback voltage. It is used to convert any periodically varying signal into a square wave.
Discussion
33.

Write any one application of logarithmic amplifier.

Answer»

It is used to multiply two input signals.
Discussion