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Semiconductors — NEET UG Physics PYQs

404 previous year questions from Semiconductors with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

404 questionsPhysicsSolutions on every page
1

For two inputs A and B and output Y, the Boolean expression for NOR gate is

MHT CET Medical 2026 Solution View → 2

For an n-type semiconductor, the relation between the number density ' n_h ' and ' n_e ' is

MHT CET Medical 2026 Solution View → 3

A silicon crystal is doped with 5 10¹⁷ cm ⁻³ atoms of boron. The electron concentration (n_e) at room temperature is (n_i = 1.5 10¹⁰ cm ⁻³)

MHT CET Medical 2026 Solution View → 4

If the current gain in common-base configuration ( ) of a transistor increases from 0.95 to 0.96, the percentage change in current gain in common-emitter configuration ( ) is appro

MHT CET Medical 2026 Solution View → 5

Out of the following what is used to detect the intensity of light ?

MHT CET Medical 2026 Solution View → 6

The color of light emitted by an LED is determined primarily by which of the following factors?

MHT CET Medical 2026 Solution View → 7

Which of the following is true for a p-type semiconductor?

MHT CET Medical 2026 Solution View → 8

In case of semiconductors, the band gap between the valence band and conduction band is

MHT CET Medical 2026 Solution View → 9

Below we give four entries for the truth table of two point input OR gate. Which two are wrong? array cccc & A & B & Y i & 1 & 0 & 1 ii & 1 & 1 & 0 iii & 0 & 0 & 1 iv & 0 & 1 & 1 a

MHT CET Medical 2026 Solution View → 10

The output of the logic circuit shown in figure will be

MHT CET Medical 2026 Solution View → 11

For a common emitter amplifier, the audio signal voltage across the collector resistance of 2 k is 4 V. If the current amplification factor of the transistor is 100 and the base re

MHT CET Medical 2026 Solution View → 12

Which of the following statements is NOT TRUE ?

MHT CET Medical 2026 Solution View → 13

The potential barrier in p-n junction diode is due to

MHT CET Medical 2026 Solution View → 14

Current through a reverse biased p-n junction, increases abruptly at

MHT CET Medical 2026 Solution View → 15

Dark current in a photo-diode depends on the

MHT CET Medical 2026 Solution View → 16

In a common emitter amplifier circuit using n-p-n transistor, the phase difference between the input and output voltages will be

MHT CET Medical 2026 Solution View → 17

The truth table for the given circuit is

MHT CET Medical 2026 Solution View → 18

Which of the following LED emits red and yellow light?

MHT CET Medical 2026 Solution View → 19

Which of the following gives output 0 in the NAND gate?

MHT CET Medical 2026 Solution View → 20

A full-wave rectifier provides a DC output voltage of 20 V . If the root mean square (RMS) value of the unwanted AC component is measured as 2 V , the ripple factor in percentage i

MHT CET Medical 2026 Solution View → 21

The logic gate equivalent to given logic gate is

MHT CET Medical 2026 Solution View → 22

In good conductor, the gap between the valence band and the conduction band is

MHT CET Medical 2026 Solution View → 23

The depletion region of a p-n junction is formed due to

MHT CET Medical 2026 Solution View → 24

In the following combination of logic gates, the outputs (y,z) are respectively.

MHT CET Medical 2026 Solution View → 25

A p-n junction photodiode is fabricated from a semiconductor with a band gap of 4 10⁻¹⁹ J. It can detect a signal of wavelength [h = 6.6 10⁻³⁴ Js , C = 3 10^8 m/s ]

MHT CET Medical 2026 Solution View → 26

In semiconductors, at room temperature

MHT CET Medical 2026 Solution View → 27

The output characteristics of a transistor in CE mode is the graph obtained by plotting

MHT CET Medical 2026 Solution View → 28

A combination of logic gates is as shown in the figure. P, Q, R and S are the inputs and X, Y and Z are outputs. When inputs P and R are "low" and Q and S are "high", the outputs X

MHT CET Medical 2026 Solution View → 29

Identify the INCORRECT statement

MHT CET Medical 2026 Solution View → 30

The components which are used in regulated power supply as rectifier, filter and voltage regulator are

MHT CET Medical 2026 Solution View → 31

To emit red or green light, LED is manufactured using

MHT CET Medical 2026 Solution View → 32

Which of the following statements is NOT true?

MHT CET Medical 2026 Solution View → 33

The below truth table corresponds to A B Y 0 0 1 1 0 1 0 1 1 1 1 0

MHT CET Medical 2026 Solution View → 34

An ideal Zener diode with breakdown voltage of -3 V is reverse biased with a negative input voltage V_i=-5 V. The magnitude of voltage difference between points B and A is :

NEET 2026 Solution View → 35

The current I in the circuit shown below is : (All diodes are ideal and identical)

NEET 2026 Solution View → 36

In the circuit shown below, the voltage appearing across the diode D will be of the form :

NEET 2026 Solution View → 37

Two statements are given below : A. When the forward bias voltage across a p-n junction diode increases above a certain threshold voltage, the diode current increases significantly

NEET 2026 Solution View → 38

Three identical p-n junction diodes D₁ , D₂ and D₃ are connected across a battery as shown in the figure. If the width of the depletion regions of D₁ , D₂ and D₃ are W₁ , W₂ and W₃

NEET 2026 Solution View → 39

A full wave rectifier circuit with diodes (D₁ ) and (D₂ ) is shown in the figure. If input supply voltage V_ in =220 (100 t) volt, then at t=15 msec

NEET 2025 Solution View → 40

The output ( Y ) of the given logic implementation is similar to the output of an/a _____ gate.

NEET 2025 Solution View → 41

When the output of an OR gate is applied as input to a NOT gate, then the combination acts as a

NEET 2024 Solution View → 42

The output Y for the inputs A and B of the given logic circuit is :

NEET 2024 Solution View → 43

A logic circuit provides the output Y as per the following truth table : array |l|l|l| & B & Y 0 & 0 & 1 0 & 1 & 0 1 & 0 & 1 1 & 1 & 0 array The expression for the output Y is :

NEET 2024 Solution View → 44

The output ( Y ) of the given logic gate is similar to the output of an/a

NEET 2024 Solution View → 45

The I-V characteristics shown above are exhibited by a

NEET 2024 Solution View → 46

Consider the following statements A and B and identify the correct answer: A. For a solar-cell, the I-V characteristics lies in the IV quadrant of the given graph. B. In a reverse

NEET 2024 Solution View → 47

The given circuit is equivalent to

NEET 2023 Solution View → 48

A full wave rectifier circuit consists of two p - n junction diodes, a centre-tapped transformer, capacitor and a load resistance. Which of these components remove the ac ripple fr

NEET 2023 Solution View → 49

The above figure shows the circuit symbol of a transistor. Select the correct statements given below: (A) The transistor has two segments of p-type semiconductor separated by a seg

NEET 2023 Solution View → 50

Given below are two statements: Statement   I : Photovoltaic devices can convert optical radiation into electricity. Statement   I I : Zener diode is designed to operate

NEET 2023 Solution View → 51

For the following logic circuit, the truth table is:

NEET 2023 Solution View → 52

A p-type extrinsic semiconductor is obtained when Germanium is doped with

NEET 2023 Solution View → 53

The incorrect statement about the property of a Zener diode is:

NEET 2022 Solution View → 54

Identify the equivalent logic gate represented by the given circuit:

NEET 2022 Solution View → 55

The collector current in a common base amplifier using n - p -n transistor is 24 ~mA . If 80 % of the electrons released by the emitter is accepted by the collector, then the base

NEET 2022 Solution View → 56

In the given circuits (a), (b) and (c), the potential drop across the two p - n junctions are equal in:

NEET 2022 Solution View → 57

In half wave rectification, if the input frequency is 60   Hz , then the output frequency would be

NEET 2022 Solution View → 58

The truth table for the given logic circuit is:

NEET 2022 Solution View → 59

The electron concentration in an undefined n -type semiconductor is the same as hole concentration in a undefined p -type semiconductor. An external field (electric) is applied acr

NEET 2021 Solution View → 60

Consider the following statements (A) and (B) and identify the correct answer. (A) A Zener diode is connected in reverse bias when used as a voltage regulator. (B) The potential ba

NEET 2021 Solution View → 61

For the given circuit, the input digital signals are applied at the terminals A , B and C . What would be the output at the terminal y ?

NEET 2021 Solution View → 62

Out of the following which one is a forward biased diode?

NEET 2020 Solution View → 63

Which of the following gate is called universal gate?

NEET 2020 Solution View → 64

A n - p - n transistor is connected in common emitter configuration in which collector voltage drop across load resistance ( 800   Ω ) connected to the collector circuit

NEET 2020 Solution View → 65

An intrinsic semiconductor is converted into n -type extrinsic semiconductor by doping it with:-

NEET 2020 Solution View → 66

The increase in the width of the depletion region in a p-n junction diode is due to:

NEET 2020 Solution View → 67

For transistor action, which of the following statements is correct?

NEET 2020 Solution View → 68

The solids which have the negative temperature coefficient of resistance are:

NEET 2020 Solution View → 69

For the logic circuit shown, the truth table is:

NEET 2020 Solution View → 70

For CE configuration n - p - n transistor. Which of the following statement is correct?

JIPMER 2019 Solution View → 71

Following circuit will act as

JIPMER 2019 Solution View → 72

The given combination will work as

JIPMER 2019 Solution View → 73

The correct Boolean operation represented by the circuit diagram drawn is,

NEET 2019 Solution View → 74

For a p - type semiconductor, which of the following statements is true?

NEET 2019 Solution View → 75

The circuit diagram shown here corresponds to the logic gate,

NEET 2019 Solution View → 76

In the circuit shown in the figure, the input voltage V i   is   20   V ,   V B E = 0   and   V C E = 0 . The values of I B ,   I C   and &#

NEET 2018 Solution View → 77

In a p - n junction diode, change in temperature due to heating

NEET 2018 Solution View → 78

In the combination of the following gates the output Y can be written in terms of inputs A and B as

NEET 2018 Solution View → 79

The following circuit represents

JIPMER 2017 Solution View → 80

In a common-emitter transistor amplifier, the audio signal voltage across the collector is 3 V. The resistance of collector is 3 kΩ . If current gain is 100 and the base resistance

NEET 2017 Solution View → 81

The given electrical network is equivalent to

NEET 2017 Solution View → 82

Which one of the following represents forward bias diode?

NEET 2017 Solution View → 83

The transfer ratio of a transistor is 50 . The input resistance of the transistor when used in the common emitter configuration is 2 k . The peak value of the collector AC current

JIPMER 2016 Solution View → 84

The truth table for the following logic circuit is

JIPMER 2016 Solution View → 85

For common emitter transistor amplifier, the audio signal voltage across the collector resistance of 2 k Ω is 4 V. If the current amplification factor of the transistor is 100 and

NEET 2016 Solution View → 86

The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance R 1 will be

NEET 2016 Solution View → 87

Consider the junction diode as ideal. The value of current flowing through AB is:

NEET 2016 Solution View → 88

What is the output Y in the following circuit, when, all the three inputs A ,   B ,   C are first 0 and then, 1 ?

NEET 2016 Solution View → 89

A NPN transistor is connected in common emitter configuration in a given amplifier. A load resistance of 800   Ω is connected in the collector circuit and the voltage dro

NEET 2016 Solution View → 90

To get output 1 for the following circuit, the correct choice for the input is:

NEET 2016 Solution View → 91

A change of 8.0 mA in the emitter current brings a change of 7.9 mA in the collector current. The value of will be

JIPMER 2015 Solution View → 92

In the given figure, a diode D is connected to an external resistance R   =   100   Ω and an e m f of 3 . 5   V If the barrier potential developed across t

NEET 2015 Solution View → 93

If in a p-n junction, a square input signal of 10 V is applied as shown, then the output across R L will be

NEET 2015 Solution View → 94

Which logic gate is represented by the following combination of logic gates?

NEET 2015 Solution View → 95

The input signal is given to a CE amplifier having a voltage gain of 150 is V i = 2 cos ⁡ 15 t + π 3 . The corresponding output signal will be:

NEET 2015 Solution View → 96

The reason of current flow in p-n junction in forward bias is

JIPMER 2014 Solution View → 97

When plate voltage in diode valve is increased from 100 V to 150 V. Then, plate current increases from 7.5 mA to 12 mA, then dynamic plate resistance will be

JIPMER 2014 Solution View → 98

The given graph represents V - I characteristic for a semiconductor device. Which of the following statement is correct?

NEET 2014 Solution View → 99

The barrier potential of a p-n junction depends on: a type of semi-conductor material b amount of doping c temperature Which one of the following is correct?

NEET 2014 Solution View → 100

Which logic gate is represented by the following combination of logic gates?

JIPMER 2013 Solution View → 101

The output from a NAND gate is divided into two in parallel and fed to another NAND gate. The resulting gate is a:

NEET 2013 Solution View → 102

In an unbiased p-n junction holes from the p-region to n -region because of:

NEET 2013 Solution View → 103

One way in which the operation of n-p-n transistor differs from of a p-n-p :

NEET 2013 Solution View → 104

In a n -type semiconductor, which of the following statement is true?

NEET 2013 Solution View → 105

The output (X) of the logic circuit shown in figure will be

NEET 2013 Solution View → 106

In a common emitter (CE) amplifier having a voltage gain G , the transistor used has transconductance 0.03 mho and current gain 25. If the above transistor is replaced with another

NEET 2013 Solution View → 107

The truth table given below is for ( A and B are the inputs, Y is the output)

JIPMER 2012 Solution View → 108

Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is

NEET 2012 Solution View → 109

In a CE transistor amplifier, the audio signal voltage across the collector resistance of 2 k is 2 ~V . If the base resistance is 1 k and the current amplification of the transisto

NEET 2012 Solution View → 110

C and Si both have same lattice structure, having 4 bonding electrons in each. However, C is insulator whereas Si is intrinsic semiconductor. This is because

NEET 2012 Solution View → 111

The figure shows a logic circuit with two inputs A and B and the output C . The voltage wave forms across A, B and C are as given. The logic circuit gate is

NEET 2012 Solution View → 112

The input resistance of a silicon transistor is 100 . Base current is changed by 40 A which results in a change in collector current by 2 ~mA . This transistor is used as a common-

NEET 2012 Solution View → 113

To get an output Y=1 in given circuit which of the following input will be correct

NEET 2012 Solution View → 114

Transfer characteristic [output voltage (V₀ )v s input voltage . (V_i ) ] for a base biased transistor in CE configuration is as shown in the figure. For using transistor as a swit

NEET 2012 Solution View → 115

Which of the following is unipolar transistor?

JIPMER 2011 Solution View → 116

A transistor is operated in common emitter configuration at V_C=2 ~V such that a change in the base current from 100 A to 300 A produces a change in the collector current from 10 ~

NEET 2011 Solution View → 117

If a small amount of antimony is added to germanium crystal

NEET 2011 Solution View → 118

In forward biasing of the p-n junction

NEET 2011 Solution View → 119

In the following figure, the diodes which are forward biased, are A. B. C. D.

NEET 2011 Solution View → 120

Pure Si at 500 ~K has equal number of electron (n_e ) and hole (n_h ) concentrations of 1.5 10¹⁶ ~m ⁻³ . Doping by indium increases n_h to 4.5 10²² ~m ⁻³ . The doped semiconductor

NEET 2011 Solution View →
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