Semiconductor Devices And Logic Gates - Modern Physics - Physics Previous Year Questions

1

2017 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2017

Which of the following semi-conducting device is used as voltage regulator?

A

LASER diode

B

Zener diode

C

Solar cell

D

Photo diode

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2

2017 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2017

The energy gap in case of which of the following is less than 3 eV ?

A

Germanium

B

Iron

C

Copper

D

Aluminium

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3

2017 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2017

In the three parts of a transistor, 'Emitter' is of

A

larger size and lightly doped

B

moderate size and heavily doped

C

thin size and heavily doped

D

large size and moderately doped

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4

2017 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2017

In the figure shown, if the diode forward voltage drop is 0.2 V , the voltage difference between $A$ and $B$ is

A

2.2 V

B

1.3 V

C

0

D

0.5 V

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5

2017 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2017

Which of the following logic gate is universal gate

A

B

C

D

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6

2018 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2018

If $A=1$ and $B=0$, then in terms of Boolean algebra, $A+\bar{B}=$

A

$B$

B

$\bar{B}$

C

$A$

D

$\bar{A}$

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7

2018 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2018

In a CE amplifier, the input AC signal to be amplified is applied across

A

forward biased emitter-base junction

B

reverse biased collector-base junction

C

reverse biased emitter-base junction

D

forward biased collector-base junction

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8

2018 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2018

The DC common emitter current gain of an $n-p-n$ transistor is 50 . The potential difference applied across the collector and emitter of a transistor used in CE configuration is, $V_{C E}=2 \mathrm{~V}$. If the collector resistance $R_C=4 \mathrm{k} \Omega$, the base current $\left(I_B\right)$ and the collector current $\left(I_C\right)$ are

A

$I_B=10 \mu \mathrm{~A}, I_C=0.5 \mathrm{~mA}$

B

$I_B=0.5 \mu \mathrm{~A}, I_C=10 \mathrm{~mA}$

C

$I_B=5 \mu \mathrm{~A}, I_C=1 \mathrm{~mA}$

D

$I_B=1 \mu \mathrm{~A}, I_C=0.5 \mathrm{~mA}$

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9

2018 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2018

The density of electron-hole pair in a pure germanium is $3 \times 10^{16} \mathrm{~m}^{-3}$ at room temperature. On doping with aluminium, the hole density increases to $4.5 \times 10^{22} \mathrm{~m}^{-3}$. Now, the electron density (in $\mathrm{m}^{-3}$ ) in doped germanium will be

A

$1 \times 10^{10}$

B

$2 \times 10^{10}$

C

$0.5 \times 10^{10}$

D

$4 \times 10^{10}$

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10

2019 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2019

For a transistor amplifier, the voltage gain

A

remains constant for all frequencies

B

is high at high and low frequencies and constant in the middle frequency range

C

is low at high and low frequencies and constant at mid frequencies

D

constant at high frequencies and low at low frequencies

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11

2019 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2019

The conductivity of semiconductor increases with increase in temperature because

A

number density of charge carriers increases

B

relaxation time increases

C

both number density of charge carriers and relaxation time increases

D

number density of current carriers increases, relaxation time decreases but effect of decrease in relaxation time is much less than increase in number density

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12

2019 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2019

In the following circuit, what are P and Q?

A

\(P = 0, Q=0\)

B

\(P=1, Q=0\)

C

\(P=0, Q=1\)

D

\(P=1, Q=1\)

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13

2020 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2020

A positive hole in a semiconductor is

A

an anti-particle of electron

B

a vacancy created when an electron leaves a covalent bond

C

absence of free electrons

D

an artificially created particle

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14

2020 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2020

In the following circuit what are P and Q

A

\(P=1, Q=0\)

B

\(P=0, Q=1\)

C

\(P=0, Q=0\)

D

\(P=1, Q=1\)

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15

2021 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2021

The circuit given represents which of the logic operations?

A

OR

B

AND

C

NOT

D

NOR

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16

2021 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2021

Identify the incorrect statement.

A

When a \(p\)-\(n\) junction diode is forward biased, then the width of the depletion region decreases.

B

When a \(p\)-\(n\) junction diode is reverse biased, the barrier potential increases.

C

A photodiode is operated in the reverse bias.

D

An LED is a lightly doped \(p\)-\(n\) junction diode which emits spontaneous radiation of forward biasing.

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17

2021 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2021

Three photodiodes \(D_1, D_2\) and \(D_3\) are made of semiconductors having band gaps of \(2.5 \mathrm{~eV}, 2 \mathrm{~eV}\) and \(3 \mathrm{~eV}\), respectively. Which one will be able to detect light of wavelength \(600 \mathrm{~nm}\) ?

A

\(D_1\) only

B

Both \(D_1\) and \(D_3\)

C

\(D_2\) only

D

All of these

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18

2022 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2022

The forbidden energy gap for Ge crystal at 0K is

A

0.71 eV

B

2.57 eV

C

6.57 eV

D

0.071 eV

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19

2022 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2022

The resistivity of a semiconductor at room temperature is in between

A

\(10^{-3}\) to \(10^6 \Omega-\mathrm{cm}\)

B

\(10^6\) tol \(0^8 \Omega-\mathrm{cm}\)

C

\(10^{10}\) to \(10^{12} \Omega-\mathrm{cm}\)

D

\(10^{-2}\) to \(10^{-5} \Omega-\mathrm{cm}\)

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20

2022 · Physics · Modern Physics · Semiconductor Devices And Logic Gates

KCET 2022

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

A

NAND

B

AND

C

NOR

D

OR

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