Question 1: Palette 1/119

NEET 2026 MCQ

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

A

$\frac{5}{3} \mathrm{~A}$

B

$\frac{5}{9} \mathrm{~A}$

C

$\frac{1}{3} \mathrm{~A}$

D

$\frac{15}{2} \mathrm{~A}$

Question 2: Palette 2/119

NEET 2026 MCQ

$ \text { In the circuit shown below, the voltage appearing across the diode } D \text { will be of the form: } $

A

B

C

D

Question 3: Palette 3/119

NEET 2026 MCQ

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.

B. This current is called reverse saturation current.

Choose the correct answer from the options given below:

A

Both Statements A and B are true

B

Statement A is true, but Statement B is false

C

Both Statements $A$ and $B$ are false

D

Statement A is false, but Statement B is true

Question 4: Palette 4/119

NEET 2026 MCQ

An ideal Zener diode with breakdown voltage of -3 V is reverse biased with a negative input voltage $V_i=-5 \mathrm{~V}$. The magnitude of voltage difference between point $B$ and $A$ is:

A

0 V

B

3 V

C

2 V

D

1 V

Question 5: Palette 5/119

NEET 2026 MCQ

Three identical p-n junction diodes $D_1, D_2$, and $D_3$ are connected across a battery as shown in the figure. If the width of the depletion regions of $D_1, D_2$ and $D_3$ are $W_1, W_2$ and $W_3$, respectively, then the correct option is:

A

$W_2>W_1=W_3$

B

$W_1>W_2>W_3$

C

$ W_3=W_1>W_2$

D

$ W_3>W_2>W_1$

Question 6: Palette 6/119

NEET 2025 MCQ

A full wave rectifier circuit with diodes $\left(D_1\right)$ and $\left(D_2\right)$ is shown in the figure. If input supply voltage $\mathrm{V}_{\text {in }}=220 \sin (100 \pi t)$ volt, then at $t=15 \mathrm{msec}$

A

$\quad D_1$ and $D_2$ both are forward biased

B

$\quad D_1$ and $D_2$ both are reverse biased

C

$\quad D_1$ is forward biased, $D_2$ is reverse biased

D

$\quad D_1$ is reverse biased, $D_2$ is forward biased.

Question 7: Palette 7/119

NEET 2025 MCQ

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

A

OR

B

NOR

C

AND

D

NAND

Question 8: Palette 8/119

NEET 2024 MCQ

The I-V characteristics shown above are exhibited by a

A

Light emitting diode

B

Zener diode

C

Photodiode

D

Solar cell

Question 9: Palette 9/119

NEET 2024 MCQ

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

A

NAND gate

B

NOR gate

C

AND gate

D

OR gate

Question 10: Palette 10/119

NEET 2024 MCQ

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

A

$A \cdot B$

B

$\bar{A} \cdot \bar{B}$

C

$A+B$

D

$\bar{A}+\bar{B}$

Question 11: Palette 11/119

NEET 2024 MCQ

A logic circuit provides the output $Y$ as per the following truth table :

The expression of the output Y is :

A

$ A \cdot B+\bar{A} $

B

$ A \cdot \bar{B}+\bar{A} $

C

$ \bar{B} $

D

B

Question 12: Palette 12/119

NEET 2024 MCQ

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 biased $p n$ junction diode, the current measured in $(\mu \mathrm{A})$, is due to majority charge carriers.

A

$A$ is correct but $B$ is incorrect

B

$A$ is incorrect but $B$ is correct

C

Both A and B are correct

D

Both $A$ and $B$ are incorrect

Question 13: Palette 13/119

NEET 2024 MCQ

$ \text { The output ( } Y \text { ) of the given logic gate is similar to the output of an/a } $

A

NAND gate

B

NOR gate

C

OR gate

D

AND gate

Question 14: Palette 14/119

NEET 2023 MCQ

On the basis of electrical conductivity, which one of the following material has the smallest resistivity?

A

Germanium

B

Silver

C

Glass

D

Silicon

Question 15: Palette 15/119

NEET 2023 MCQ

The given circuit is equivalent to:

A

B

C

D

Question 16: Palette 16/119

NEET 2023 MCQ

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

A

Antimony

B

Phosphorous

C

Arsenic

D

Boron

Question 17: Palette 17/119

NEET 2023 MCQ

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 segment of n-type semiconductor.

(B) The emitter is of moderate size and heavily doped.

(C) The central segment is thin and lightly doped.

(D) The emitter base junction is reverse biased in common emitter amplifier circuit.

A

(C) and (D)

B

(A) and (D)

C

(A) and (B)

D

(B) and (C)

Question 18: Palette 18/119

NEET 2023 MCQ

Given below are two statements:

Statement I : Photovoltaic devices can convert optical radiation into electricity.

Statement II : Zener diode is designed to operate under reverse bias in breakdown region.

In the light of the above statements, choose the most appropriate answer from the options given below :

A

Both Statement I and Statement II are incorrect.

B

Statement I is correct but Statement II is incorrect.

C

Statement I is incorrect but Statement II is correct.

D

Both Statement I and Statement II are correct

Question 19: Palette 19/119

NEET 2023 MCQ

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 from the rectified output?

A

p-n junction diodes

B

Capacitor

C

Load resistance

D

A centre-tapped transformer

Question 20: Palette 20/119

NEET 2023 MCQ

For the following logic circuit, the truth table is:

A

A	B	Y
0	0	0
0	1	1
1	0	1
1	1	1

B

A	B	Y
0	0	1
0	1	0
1	0	1
1	1	0

C

A	B	Y
0	0	0
0	1	0
1	0	0
1	1	1

D

A	B	Y
0	0	1
0	1	1
1	0	1
1	1	0

Question 21: Palette 21/119

NEET 2022 MCQ

Identify the equivalent logic gate represented by the given circuit

A

NAND

B

OR

C

NOR

D

AND

Question 22: Palette 22/119

NEET 2022 MCQ

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

A

p and n regions of Zener diode are heavily doped

B

Zener voltage remains constant at breakdown

C

It is designed to operate under reverse bias

D

Depletion region formed is very wide

Question 23: Palette 23/119

NEET 2022 MCQ

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 current is numerically :

A

3 mA and entering the base

B

6 mA and leaving the base

C

3 mA and leaving the base

D

6 mA and entering the base

Question 24: Palette 24/119

NEET 2022 MCQ

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

A

Circuit (a) only

B

Circuit (b) only

C

Circuit (c) only

D

Both circuits (a) and (c)

Question 25: Palette 25/119

NEET 2022 MCQ

As the temperature increases, the electrical resistance

A

Increases for both conductors and semiconductors

B

Decreases for both conductors and semiconductors

C

Increases for conductors but decreases for semiconductors

D

Decreases for conductors but increases for semiconductors

Question 26: Palette 26/119

NEET 2022 MCQ

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

A

Zero

B

30 Hz

C

60 Hz

D

120 Hz

Question 27: Palette 27/119

NEET 2022 MCQ

The truth table for the given logic circuit is

A

B

C

D

Question 28: Palette 28/119

NEET 2021 MCQ

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 barrier of p-n junction lies between 0.1 V to 0.3 V.

A

(A) is incorrect but (B) is correct.

B

(A) and (B) both are correct.

C

(A) and (B) both are incorrect.

D

(A) is correct and (B) is incorrect.

Question 29: Palette 29/119

NEET 2021 MCQ

The electron concentration in an n-type semiconductor is the same as hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.

A

No current will flow in p-type, current will only flow in n-type

B

Current in n-type = current in p-type

C

current in p-type > current in n-type

D

current in n-type > current in p-type

Question 30: Palette 30/119

NEET 2021 MCQ

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?

A

B

C

D

Question 31: Palette 31/119

NEET 2020 MCQ

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

A

Base, emitter and collector regions should have same size.

B

Both emitter junction as well as the collector junction are forwarded biased.

C

The base region must be very thin and lightly doped.

D

Base, emitter and collector regions should have same doping concentrations.

Question 32: Palette 32/119

NEET 2020 MCQ

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

A

reverse bias only

B

both forward bias and reverse bias

C

increase in forward current

D

forward bias only

Question 33: Palette 33/119

NEET 2020 MCQ

For the logic circuit shown, the truth table is :

A

A	B	Y
0	0	0
0	1	1
1	0	1
1	1	1

B

A	B	Y
0	0	1
0	1	1
1	0	1
1	1	0

C

A	B	Y
0	0	1
0	1	0
1	0	0
1	1	0

D

A	B	Y
0	0	0
0	1	0
1	0	0
1	1	1

Question 34: Palette 34/119

NEET 2019 MCQ

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

A

OR

B

NAND

C

NOR

D

AND

Question 35: Palette 35/119

NEET 2019 MCQ

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

A

Holes are the majority carriers and trivalent atoms are the dopants.

B

Holes are the majority carriers and pentavalent atoms are the dopants.

C

Electrons are the majority carriers and pentavalent atoms are the dopants

D

Electrons are the majority carriers and trivalent atoms are the dopants.

Question 36: Palette 36/119

NEET 2018 MCQ

In the circuit shown in the figure, the input voltage V_i is 20 V, V_BE = 0 and V_CE = 0. The values of I_B , I_C and $\beta $ are given by

A

I_B = 40 $\mu $A, I_C = 10 mA, $\beta $ = 250

B

I_B = 25 $\mu $A, I_C = 5 mA, $\beta $ = 200

C

I_B = 20 $\mu $A, I_C = 5 mA, $\beta $ = 250

D

I_B = 40 $\mu $A, I_C = 5 mA, $\beta $ = 125

Question 37: Palette 37/119

NEET 2018 MCQ

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

A

$\overline {A.B} $

B

$A.\overline B + \overline A .B$

C

$\overline {A.B} + A.B$

D

$\overline {A + B} $

Question 38: Palette 38/119

NEET 2018 MCQ

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

A

affects only reverse resistance

B

affects only forward resistance

C

does not affect resistance of p-n junction

D

affects the overall V - I characteristics of p-n junction

Question 39: Palette 39/119

NEET 2017 MCQ

In a common emitter transistor amplifier the audio sgnal voltage across the collector is 3 V. The resistance of collector is 3 k$\Omega $. If current gain is 100 and the base resistance is 2 k$\Omega $, the voltage and power gain of the amplifier is

A

15 and 200

B

150 and 15000

C

20 and 2000

D

200 and 1000

Question 40: Palette 40/119

NEET 2017 MCQ

The given electrical network is equivalent to

A

OR gate

B

NOR gate

C

NOT gate

D

AND gate

Question 41: Palette 41/119

NEET 2017 MCQ

Which one of the following represents forward bias diode ?

A

B

C

D

Question 42: Palette 42/119

NEET 2016 MCQ

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

A

0, 1

B

0, 0

C

1, 0

D

1, 1

Question 43: Palette 43/119

NEET 2016 MCQ

The given circuit has two ideal diodes connected as shown in the figure. The current flowing through the resistance R₁ will be

A

2.5 A

B

10.0 A

C

1.43 A

D

3.13 A

Question 44: Palette 44/119

NEET 2016 MCQ

For CE transistor amplifier, the aufio signal voltage across the collector resistance of 2 k$\Omega $ is 4 V. If the current amplification factor of the transistor is 100 and the base resistance is 1 k$\Omega $, then the input signal voltage is

A

10 mV

B

20 mV

C

30 mV

D

15 mV

Question 45: Palette 45/119

NEET 2016 MCQ

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

A

A = 1, B = 1, C = 0

B

A = 1, B = 0, C = 1

C

A = 0, B = 1, C = 0

D

A = 1, B = 0, C = 0

Question 46: Palette 46/119

NEET 2016 MCQ

A npn transistor is connected in common emitter configuration in a given amplifier. A load resistance of 800 $\Omega $ is connected in the collector circuit and the voltage frop across it is 0.8 V. If the current amplification factor is 0.96 and the input resistance of the circuit is 192 $\Omega $, the voltage gain and the power gain of the amplifier will respectively be

A

4, 4

B

4, 3.69

C

4, 3.84

D

3.69, 3.84

Question 47: Palette 47/119

NEET 2016 MCQ

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

A

10^$-$1 A

B

10^$-$3 A

C

0 A

D

10^$-$2 A

Question 48: Palette 48/119

NEET 2015 MCQ

The input signal given to a CE amplifier having a voltage gain of 150 is V_i = 2cos(15t + ${\pi \over 3}$). The corresponding output signal will be

A

2cos$\left( {15t + {{5\pi } \over 6}} \right)$

B

300cos$\left( {15t + {{4\pi } \over 3}} \right)$

C

300cos$\left( {15t + {{\pi } \over 3}} \right)$

D

75cos$\left( {15t + {{2\pi } \over 3}} \right)$

Question 49: Palette 49/119

NEET 2015 MCQ

In the given figure, a diode D is connected to an external resistance R = 100 $\Omega $ and an e.m.f. of 3.5 V. If the barrier potential developed across the diode is 0.5 V, the current in the citcuit will be

A

20 mA

B

35 mA

C

30 mA

D

40 mA

Question 50: Palette 50/119

NEET 2015 MCQ

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

A

AND

B

NOR

C

OR

D

NAND

Question 51: Palette 51/119

NEET 2015 MCQ

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

A

B

C

D

Question 52: Palette 52/119

NEET 2014 MCQ

The barrier potential of a p-n junction depends on
(1)   type of semiconductor material
(2)   amount of doping

(3)   temperature

Which one of the following is correct ?

A

(1) and (2) only

B

(2) only

C

(2) and (3) only

D

(1), (2) and (3)

Question 53: Palette 53/119

NEET 2014 MCQ

The given graph represents V-I characteristic for a semiconductor device.



Which of the following statement is correct ?

A

It is V-I characteristic for solar cell where, point A represents open circuit voltage and point B short circuit current.

B

It is for a solar cell and popints A and B represent open circuit voltage and current, respectively.

C

It is for a photodiode and points A and B represent open circuit voltage and current, respectively.

D

It is for a LED and points A and B represent open circuit voltage and short circuit current, respectively.

Question 54: Palette 54/119

NEET 2013 MCQ

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

A

AND gate

B

NOR gate

C

OR gate

D

NOT gate

Question 55: Palette 55/119

NEET 2013 MCQ

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

A

The emitter junction injects minority carries into the base region of the p-n-p

B

The emitter injects holes into the base of the p-n-p and electrons into the base region of n-p-n

C

The emitter injects holes into the base of n-p-n

D

The emitter junction is reversed biased in n-p-n

Question 56: Palette 56/119

NEET 2013 MCQ

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

A

The attraction of free electrons of n-region.

B

The higher hole concentration in p-region than that in n-region.

C

The higher concentration of electrons in the n-region than that in the p-region.

D

The potential difference across the p-n junction.

Question 57: Palette 57/119

NEET 2013 MCQ

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

A

Holes are minority carries and pentavalent atoms are dopants.

B

Holes are majority carries and trivalent atoms are dopants.

C

Electrons are majority carries and trivalent atoms are dopants.

D

Electrons are minority carriers and pentavalent atoms are dopants.

Question 58: Palette 58/119

NEET 2013 MCQ

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

A

X = A . B

B

X = $\overline {A + B} $

C

X = $\overline {\overline A } .\overline {\overline B } $

D

X = $\overline {A.B} $

Question 59: Palette 59/119

NEET 2013 MCQ

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 one with transconductance 0.02 mho and current gain 20, the voltage gain will be

A

${1 \over 3}G$

B

${5 \over 4}G$

C

${2 \over 3}G$

D

1.5G

Question 60: Palette 60/119

NEET 2012 MCQ

The input resistance of a silicon transistor is 100 $\Omega $. Base current is changed by 40 $\mu $A which results in a change in collector current by 2 mA. This transistor is used as a common emitter amplifier with a load resistance of 4 k$\Omega $. The voltage gain of the amplifier is

A

2000

B

3000

C

4000

D

1000

Question 61: Palette 61/119

NEET 2012 MCQ

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

A

A $ \to $ 1,  B $ \to $ 0,  C $ \to $ 0

B

A $ \to $ 1,  B $ \to $ 0,  C $ \to $ 1

C

A $ \to $ 1,  B $ \to $ 1,  C $ \to $ 0

D

A $ \to $ 0,  B $ \to $ 1,  C $ \to $ 0

Question 62: Palette 62/119

NEET 2012 MCQ

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

A

In case of C the valence band is not completely filled at absolute zero temperature.

B

In case of C the conduction band is partly filled even at absolute zero temperature.

C

The four bonding electrons in the case of C lie in the second orbit, whereas in the case of Si they lie in the third.

D

The four bonding electrons in the case of C lie in the third orbit , whereas for Si they lie in the fourth orbit.

Question 63: Palette 63/119

NEET 2012 MCQ

Transfer characteristics [output voltage (V₀) vs input voltage (V_i)] for a base biased transistor in CE configuration is as shown in the figure. For using transistor as a switch, it is used

A

in region III

B

both in region (I) and (III)

C

in region II

D

in region I

Question 64: Palette 64/119

NEET 2012 MCQ

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

A

0.75 A

B

zero

C

0.25 A

D

0.5 A

Question 65: Palette 65/119

NEET 2012 MCQ

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

A

OR gate

B

NOR gate

C

AND gate

D

NAND gate

Question 66: Palette 66/119

NEET 2012 MCQ

In a CE transistor amplifier, the audio signal voltage across the collector resistance of 2 k$\Omega $ is 2 V. If the base resistance is 1 k$\Omega $ and the current amplification of the transistor is 100, the input signal voltage is

A

0.1 V

B

1.0 V

C

1 mV

D

10 mV

Question 67: Palette 67/119

NEET 2011 MCQ

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

A

p-type having electron concentration n_e = 5 $ \times $ 10⁹ m^$-$3

B

n-type with electron concentration n_e = 5 $ \times $ 10²² m^$-$3

C

p-type with electron concentration n_e = 2.5 $ \times $ 10¹⁰ m^$-$3

D

n-type with electron concentration n_e = 2.5 $ \times $ 10²³ m^$-$3

Question 68: Palette 68/119

NEET 2011 MCQ

A Zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the diode is

A

5 mA

B

10 mA

C

15 mA

D

20 mA

Question 69: Palette 69/119

NEET 2011 MCQ

In the following figure, the diodes which are forward biased, are

A

(A), (B) and (D)

B

(C) only

C

(C) and (A)

D

(B) and (D)

Question 70: Palette 70/119

NEET 2011 MCQ

In forward biasing of the p-n junction

A

the positive terminal of the battery is connected to p-side and the depletion region becomes thick.

B

the positive terminal of the battery is connected to n-side and the depletion region becomes thin.

C

the positive terminal of the battery is connected to n-side and the depletion region becomes thick.

D

the positive terminal of the battery is connected to p-side and the depletion region becomes thin.

Question 71: Palette 71/119

NEET 2011 MCQ

If a small amount of antimony is added to germanium crystal

A

it becomes a p-type semiconductor

B

the antimony becomes an acceptor atom

C

there will be more free electrons than holes in the semiconductor

D

its resistance is increased

Question 72: Palette 72/119

NEET 2011 MCQ

A transistor is operated in common emitter configuration at V_C = 2 V such that a change in the base current from 100 $\mu $A to 300 $\mu $A produces a change in the collector current from 10 mA to 20 mA. The current gain is

A

50

B

75

C

100

D

25

Question 73: Palette 73/119

NEET 2011 MCQ

Symbolic representation of four logic gates are shown as



Pick out which ones are for AND, NAND and NOT gates, respectively

A

(ii), (iii) and (iv)

B

(iii), (ii) and (i)

C

(iii), (ii) and (iv)

D

(iii), (iv) and (ii)

Question 74: Palette 74/119

NEET 2010 MCQ

The following figure shows a logic gate circuit with two inputs A and B and the output Y. The voltage waveforms of A, B and Y are as given.



The logic gate is

A

NOR gate

B

OR gate

C

AND gate

D

NAND gate

Question 75: Palette 75/119

NEET 2010 MCQ

For transistor action
(1)  Base, emitter and collector regions should have similar size and doping concentrations.
(2)  The base region must be vety thin and lightly doped.
(3)  The emitter-base junction is forward biased and base-collector junction is reverse biased.
(4)  Both the emitter-base junction as well as the base-collector junction are forward biased.

Which one of the following pairs of statements is correct?

A

(4) and (1)

B

(1) and (2)

C

(2) and (3)

D

(3) and (4)

Question 76: Palette 76/119

NEET 2010 MCQ

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

A

A $ \to $ 1,  B $ \to $ 0,  C $ \to $ 0

B

A $ \to $ 1,  B $ \to $ 0,  C $ \to $ 1

C

A $ \to $ 1,  B $ \to $ 1,  C $ \to $ 0

D

A $ \to $ 0,  B $ \to $ 1,  C $ \to $ 0

Question 77: Palette 77/119

NEET 2010 MCQ

A common emitter amplifier has a voltage gain of 50, an input impedance of 100 $\Omega $ and an output impedance of 200 $\Omega $. The power gain of the amplifier is

A

500

B

1000

C

1250

D

50

Question 78: Palette 78/119

NEET 2010 MCQ

Which one of the following statement is false ?

A

Pure Si doped with trivalent impurities gives a p-type semiconductor.

B

Majority carries in a n-type semiconductor are holes.

C

Minority carries in a p-type semiconductor are electrons.

D

The resistance of intrinisic semiconductor decreases with increase of temperature.

Question 79: Palette 79/119

NEET 2010 MCQ

The device that can act as a complete electronic circuit is

A

junction diode

B

integrated circuit

C

junction transistor

D

zener diode

Question 80: Palette 80/119

NEET 2010 MCQ

Which one of the following bonds produces a solid that reflects light in the visible region and whose electrical conductivity decreases with temperature and has high melting point ?

A

metallic bonding

B

van der Waal's bonding

C

ionic bonding

D

covalent bonding

Question 81: Palette 81/119

NEET 2009 MCQ

A transistor is operated in common-emitter configuration at V_C = 2V such that a change in the base current from 100 $\mu $A to 200 $\mu $A produces a change in the collector current from 5 mA to 10 mA. The current gain is

A

100

B

150

C

50

D

75

Question 82: Palette 82/119

NEET 2009 MCQ

A p-n photodiode is fabricated from a semiconductor with a band gap of 2.5 eV. It can detect a signal of wavelength

A

4000 nm

B

6000 nm

C

4000 $\mathop A\limits^ \circ $

D

6000 $\mathop A\limits^ \circ $

Question 83: Palette 83/119

NEET 2009 MCQ

Sodium has body centred packing. Distance between two nearest atoms is 3.7 $\mathop A\limits^ \circ $. The lattice parameter is

A

4.3 $\mathop A\limits^ \circ $

B

3.0 $\mathop A\limits^ \circ $

C

8.6 $\mathop A\limits^ \circ $

D

6.8 $\mathop A\limits^ \circ $

Question 84: Palette 84/119

NEET 2009 MCQ

The symbolic representation of four logic gates are given below



The logic symbols for OR, NOT and NAND gates are respectively

A

(iv), (i), (iii)

B

(iv), (ii), (i)

C

(i), (iii), (iv)

D

(iii), (iv), (ii)

Question 85: Palette 85/119

NEET 2008 MCQ

The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be

A

1.25

B

100

C

90

D

10

Question 86: Palette 86/119

NEET 2008 MCQ

A p-n photodiode is made of a material with a band gap of 2.0 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly

A

1 $ \times $ 10¹⁴ Hz

B

20 $ \times $ 10¹⁴ Hz

C

10 $ \times $ 10¹⁴ Hz

D

5 $ \times $ 10¹⁴ Hz

Question 87: Palette 87/119

NEET 2008 MCQ

If the lattice parameter for a crystalline structure is 3.6 $\mathop A\limits^ \circ $, then the atomic radius in fcc crystal is

A

2.92 $\mathop A\limits^ \circ $

B

1.27 $\mathop A\limits^ \circ $

C

1.81 $\mathop A\limits^ \circ $

D

2.10 $\mathop A\limits^ \circ $

Question 88: Palette 88/119

NEET 2007 MCQ

For a cubic crystal structure which one of the following relations indicating the cell characteristics is correct ?

A

a $ \ne $ b $ \ne $ c  and  $\alpha $ = $\beta $ = $\gamma $ = 90^o

B

a = b = c  and  $\alpha $ $ \ne $ $\beta $ $ \ne $ $\gamma $ = 90^o

C

a = b = c  and  $\alpha $ = $\beta $ = $\gamma $ = 90^o

D

a $ \ne $ b $ \ne $ c  and  ;$\alpha $ $ \ne $ $\beta $ $ \ne $  and  $\gamma $ = 90^o

Question 89: Palette 89/119

NEET 2007 MCQ

In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is

A

an insulator

B

a metal

C

an n-type semiconductor

D

a p-type semiconductor.

Question 90: Palette 90/119

NEET 2007 MCQ

Which one of the following represents forward bias diode ?

A

B

C

D

Question 91: Palette 91/119

NEET 2007 MCQ

In the following circuit, the output Y for all possible inputs A and B is expressed by the truth table.

A

$\matrix{ A & B & Y \cr 0 & 0 & 1 \cr 0 & 1 & 1 \cr 1 & 0 & 1 \cr 1 & 1 & 0 \cr } $

B

$\matrix{ A & B & Y \cr 0 & 0 & 1 \cr 0 & 1 & 0 \cr 1 & 0 & 0 \cr 1 & 1 & 0 \cr } $

C

$\matrix{ A & B & Y \cr 0 & 0 & 0 \cr 0 & 1 & 1 \cr 1 & 0 & 1 \cr 1 & 1 & 1 \cr } $

D

$\matrix{ A & B & Y \cr 0 & 0 & 0 \cr 0 & 1 & 0 \cr 1 & 0 & 0 \cr 1 & 1 & 1 \cr } $

Question 92: Palette 92/119

NEET 2006 MCQ

The following figure shows a logic gate circuit with two inputs A and B and the output C.



The voltage waveforms of A, B and C are as shown below.



The logic circuit gate is

A

OR gate

B

AND gate

C

NAND gate

D

NOR gate

Question 93: Palette 93/119

NEET 2006 MCQ

A transistor is operated in common emitter configuration at constant collector voltage V_C = 1.5 V such that a change in the base current from 100 $\mu $A to 150 $\mu $A profuces a change in the collector current from 5 mA to 10 mA. The current gain $\beta $ is

A

50

B

67

C

75

D

100

Question 94: Palette 94/119

NEET 2006 MCQ

Which one of the following represents forward bias diode ?

A

B

C

D

Question 95: Palette 95/119

NEET 2005 MCQ

In a p-n junction photo cell, the value of the photo-electromotive force profuced by monochromatic light is proportional to

A

The barrier voltage at the p-n junction.

B

The intensity of the light falling on the cell.

C

The frequency of the light falling on the cell.

D

The voltage applied at the p-n junction.

Question 96: Palette 96/119

NEET 2005 MCQ

Choose the only false statement from the following.

A

In conductors the valence and conduction bands overlap.

B

Substances with energy gap of the order of 10 eV are insulators.

C

The resistivity of a semiconductor increases with increase in temperature.

D

The conductivity of a semiconductor increases with increase in temperature.

Question 97: Palette 97/119

NEET 2005 MCQ

Zener diode is used for

A

amplification

B

rectification

C

stabilisation

D

producing oscillations in an oscillator.

Question 98: Palette 98/119

NEET 2005 MCQ

Copper has face centered cubic (fcc) lattice with interatomic spacing equal to 2.54 $\mathop A\limits^ \circ $. The value of lattice constant for this lattice is

A

2.54 $\mathop A\limits^ \circ $

B

3.59 $\mathop A\limits^ \circ $

C

1.27 $\mathop A\limits^ \circ $

D

5.08 $\mathop A\limits^ \circ $

Question 99: Palette 99/119

NEET 2005 MCQ

Application of a forward bias to a p-n junction

A

widens the depletion zone

B

increases the potential difference across the depletion zone

C

increases the number of donors on the n side

D

decreases the electric field in the depletion zone.

Question 100: Palette 100/119

NEET 2005 MCQ

Carbon, silicon and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by (E_g)_C, (E_g)_si and (E_g)_Ge respectively. Which one of the following relationships is true in their case?

A

(E_g)_C > (E_g)_Si

B

(E_g)_C < (E_g)_Si

C

(E_g)_C = (E_g)_Si

D

(E_g)_C < (E_g)_Ge.

Question 101: Palette 101/119

NEET 2004 MCQ

In semiconductors at a room temperature

A

the valence band is partially empty and the conduction band is partially filled

B

the valence band is completely filled and the conduction band is partially filled

C

the valence band is completely filled

D

the conduction band is completely empty

Question 102: Palette 102/119

NEET 2004 MCQ

The output of OR gate is 1

A

if both inputs are zero

B

if either or both inputs are 1

C

only if both inputs are 1

D

if either inputs is zero

Question 103: Palette 103/119

NEET 2004 MCQ

Of the diodes shown in the following diagrams, which one is reverse biased ?

A

B

C

D

Question 104: Palette 104/119

NEET 2004 MCQ

The peak voltage in the output of a half wave diode rectifier fed with a sinusoidal signal without filter is 10 V. The d.c. component of the output voltage is

A

(10/$\sqrt 2 $) V

B

$\left( {{{10} \over \pi }} \right)V$

C

10 V

D

(20/$\pi $) V

Question 105: Palette 105/119

NEET 2003 MCQ

If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be

A

25 Hz

B

50 Hz

C

70.7 Hz

D

100 Hz

Question 106: Palette 106/119

NEET 2003 MCQ

A n-p-n transistor conducts when

A

both collector and emitter are positive with respect to the base

B

collector is positive and emitter is negative with respect to the base

C

collector is positive and emitter is at same potential as the base

D

both collector and emitter are negative with respect to the base

Question 107: Palette 107/119

NEET 2003 MCQ

Barrier potential of a p-n junction diode does not depened on

A

diode design

B

temperature

C

forward bias

D

doping density

Question 108: Palette 108/119

NEET 2003 MCQ

Reverse bias applied to a junction diode

A

lowers the potential barrier

B

raises the potential barrier

C

increases the majority carrier current

D

increases the minority carrier current

Question 109: Palette 109/119

NEET 2002 MCQ

The given truth table is for which logic gate

              $\matrix{ A & B & Y \cr 1 & 1 & 0 \cr 0 & 1 & 1 \cr 1 & 0 & 1 \cr 0 & 0 & 1 \cr } $

A

NAND

B

XOR

C

NOR

D

OR.

Question 110: Palette 110/119

NEET 2002 MCQ

In a p-n junction

A

high potential at n side and low potential at p side

B

high potential at P side and low potential at n side

C

p and n both are at same potential

D

undetermined.

Question 111: Palette 111/119

NEET 2002 MCQ

For the given circuit of p-n junction diode which is correct

A

in forward bias the voltage across R is V

B

in reverse bias the voltage across R is V

C

in forward bias the voltage across R is 2V

D

in reverse bias the voltage across R is 2V.

Question 112: Palette 112/119

NEET 2002 MCQ

Number of atom per unit cell in B.C.C.

A

9

B

4

C

2

D

1

Question 113: Palette 113/119

NEET 2002 MCQ

For a transistor ${{{I_C}} \over {{I_E}}}$ = 0.96, then current gain for common emitter is

A

12

B

6

C

48

D

24

Question 114: Palette 114/119

NEET 2001 MCQ

The given truth table is for which logic gate

              $\matrix{ A & B & Y \cr 1 & 1 & 0 \cr 0 & 1 & 1 \cr 1 & 0 & 1 \cr 0 & 0 & 1 \cr } $

A

NAND

B

XOR

C

NOR

D

OR

Question 115: Palette 115/119

NEET 2001 MCQ

For a common base circuit if ${{{I_C}} \over {{I_E}}}$ = 0.98 then current gain for common emitter circuit will be

A

49

B

98

C

4.9

D

25.5.

Question 116: Palette 116/119

NEET 2001 MCQ

The current in the circuit will be

A

5/40 A

B

5/50 A

C

5/10 A

D

5/20 A

Question 117: Palette 117/119

NEET 2000 MCQ

From the following diode circuit, which diode is in forward biased condition

A

B

C

D

Question 118: Palette 118/119

NEET 2000 MCQ

The cations and anions are arranged in alternate form in

A

metallic crystal

B

ionic crystal

C

covalent crystal

D

semi-conductor crystal.

Question 119: Palette 119/119

NEET 2000 MCQ

The correct relation for $\alpha $, $\beta $ for a transistor

A

$\beta = {{1 - \alpha } \over \alpha }$

B

$\beta = {\alpha \over {1 - \alpha }}$

C

$\alpha = {{\beta - 1} \over \beta }$

D

$\alpha \beta = 1$