Engineering Physics MCQ (30) 2026

In the circuit shown in the figure, the Thevenin voltage VTh and Thevenin resistance RTh as seen by the load resistance RL (= 1 k$$\Omega $$) are respectively <img src="/images/question-image/engineering-physics/electronics/1689766108-in-the-circuit-shown-in-the-figure.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

15 V, 1 k$$\Omega $$

খ

30 V, 4 k$$\Omega $$

গ

20 V, 2 k$$\Omega $$

ঘ

10 V, 5 k$$\Omega $$

An analog voltage V is converted into 2-bit binary number. The minimum number of comparators required and their reference voltages are

ক

$$3,\,\left( {\frac{V}{4},\,\frac{V}{2},\,\frac{{3V}}{4}} \right)$$

খ

$$3,\,\left( {\frac{V}{3},\,\frac{{2V}}{3},\,V} \right)$$

গ

$$4,\,\left( {\frac{V}{5},\,\frac{{2V}}{5},\,\frac{{3V}}{5},\,\frac{{4V}}{5}} \right)$$

ঘ

$$4,\,\left( {\frac{V}{4},\,\frac{V}{2},\,\frac{{3V}}{5},\,V} \right)$$

The high input impedance of Field Effect Transistor (FET) amplifier is due to

ক

the pinch-off voltage

খ

its very low gate current

গ

the source and drain being far apart

ঘ

the geometry of the FET

<img src="/images/question-image/engineering-physics/electronics/1689765499-pick-the-correct-statement-based-on-the.png" title="Electronics mcq question image" alt="Electronics mcq question image"> Pick the correct statement based on the above circuit.

ক

The maximum Zener current IZ(max), when RL = 10 k$$\Omega $$, is 15 mA

খ

The maximum Zener current IZ(max), when RL = 10 k$$\Omega $$, is 5 mA

গ

With Vin = 20 V, IL = IZ, when RL = 2 k$$\Omega $$

ঘ

The power dissipated across the Zener, when RL = 10 k$$\Omega $$ and Vin = 20 V is 100 mW

For any set of inputs, A and B, the following circuits give the same output Q, except one. Which one is it?

ক

খ

গ

ঘ

The circuit, shown is based on ideal operational amplifiers. It acts as a <img src="/images/question-image/engineering-physics/electronics/1689760342-the-circuit-shown-is-based-on-ideal-operational.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

subtractor

খ

buffer amplifier

গ

adder

ঘ

divider

Consider the following circuit: <img src="/images/question-image/engineering-physics/electronics/1689759945-consider-the-following-circuit.png" title="Electronics mcq question image" alt="Electronics mcq question image"> Which of the following correctly represents the output Vout corresponding to the input Vin?

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খ

গ

ঘ

Which of the following statements is correct for a common emitter amplifier circuit?

ক

The output is taken from the emitter

খ

There is 180° phase shift between input and output voltages

গ

There is no phase shift between input and output voltages

ঘ

Both p-n junctions are forward biased

For an intrinsic semiconductor, $$m_e^ * $$ and $$m_h^ * $$ are respectively, the effective masses of electrons and holes near the corresponding band edges. At a finite temperature, the position of the Fermi level

ক

depends on $$m_e^ * $$ but not on $$m_h^ * $$

খ

depends on $$m_h^ * $$ but not on $$m_e^ * $$

গ

depends on both $$m_e^ * $$ and $$m_h^ * $$

ঘ

depends neither on $$m_e^ * $$ nor on $$m_h^ * $$

The voltage resolution of a 12-bit Digital to Analog Converter (DAC), whose output varies from -10 V to +10 V, is approximately

ক

1 mV

খ

5 mV

গ

20 mV

ঘ

100 mV

A piece of semiconducting material is introduced into a circuit. If the temperature of the material is raised, the circuit current will

ক

increase

খ

remain the same

গ

decrease

ঘ

cease to flow

An avalanche effect is observed in a diode when

ক

the forward voltage is less than the breakdown voltage

খ

the forward voltage exceeds the breakdown voltage

গ

the reverse voltage exceeds the breakdown voltage

ঘ

the diode is heavily doped and forward biased

The tank circuit of a Hartley oscillator is shown in the figure. If M is the mutual inductance between the inductors, the oscillation frequency is <img src="/images/question-image/engineering-physics/electronics/1689754663-the-tank-circuit-of-a-hartley-oscillator.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

$$\frac{1}{{2\pi \sqrt {\left( {{L_1} + {L_2} + 2M} \right)C} }}$$

খ

$$\frac{1}{{2\pi \sqrt {\left( {{L_1} + {L_2} - 2M} \right)C} }}$$

গ

$$\frac{1}{{2\pi \sqrt {\left( {{L_1} + {L_2} + M} \right)C} }}$$

ঘ

$$\frac{1}{{2\pi \sqrt {\left( {{L_1} + {L_2} - M} \right)C} }}$$

In order to obtain a solution of the differential equation $$\frac{{{d^2}V}}{{d{t^2}}} - 2\frac{{dV}}{{dt}} + {V_1} = 0,$$ involving voltages V(t) and V1, an operational amplifier (op-amp) circuit would require at least

ক

two op-amp integrators and one op-amp adder

খ

two op-amp differentiators and one op-amp adder

গ

one op-amp integrator and one op-amp adder

ঘ

one op-amp integrator and one op-amp differentiator and one op-amp adder

In one of the following circuits, negative feedback does not operate for a negative input. Which one is it? The op-amps are running from ±15 V supplies.

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খ

গ

ঘ

The simplest logic gate circuit corresponding to the Boolean expression, Y = P + PQ is

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খ

গ

ঘ

In a typical n-p-n transistor, the doping concentrations in emitter, base and collector regions are CE, CB and CC respectively. These satisfy the relation,

ক

CE > CC > CB

খ

CE > CB > CC

গ

CC > CB > CE

ঘ

CE = CC > CB

A field effect transistor is a

ক

unipolar device

খ

special type of bipolar junction transistor

গ

unijunction device

ঘ

device with low input impedance

The circuit shown in the figure can be used as a <img src="/images/question-image/engineering-physics/electronics/1689750983-the-circuit-shown-in-the-figure-can.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

high-pass filter or a differentiator

খ

low-pass filter or a differentiator

গ

high-pass filter or an integrator

ঘ

low-pass filter or an integrator

A bipolar junction transistor with one junction forward biased and either the collector or emitter open, operates in the

ক

cut-off region

খ

saturation region

গ

pinch-off region

ঘ

active region

In an n-p-n transistor, the leakage current consists of

ক

electrons moving from the base to the emitter

খ

electrons moving from the collector to the base

গ

electrons moving from the collector to the emitter

ঘ

electrons moving from the base to the collector

Which one of the sets of values given below does not satisfy the Boolean relation R = PQ' (where, Q' denotes not Q)?

ক

P = 1, Q = 1, R = 0

খ

P = 1, Q = 1, R = 1

গ

P = 0, Q = 0, R = 0

ঘ

P = 0, Q = 1, R = 1

The largest analog output voltage from a 6-bit Digital to Analog Converter (DAC) which produces 1.0 V output for a digital input of 010100, is

ক

1.6 V

খ

2.9 V

গ

3.15 V

ঘ

5.0 V

The low-pass active filter shown in the figure has a cut-off frequency of 2 kHz and a pass band gain of 1.5. The values of the resistors are <img src="/images/question-image/engineering-physics/electronics/1689750148-the-low-pass-active-filter-shown-in.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

R1 = 10 k$$\Omega $$; R2 = 1.3 $$\Omega $$

খ

R1 = 30 k$$\Omega $$; R2 = 1.3 $$\Omega $$

গ

R1 = 10 k$$\Omega $$; R2 = 1.7 $$\Omega $$

ঘ

R1 = 30 k$$\Omega $$; R2 = 1.7 $$\Omega $$

A sinusoidal input voltage Vin of frequency ω is fed to the circuit shown in the figure, where C1 ≫ C2. If Vm is the peak value of the input voltage, then output voltage (Vout) is <img src="/images/question-image/engineering-physics/electronics/1689749703-a-sinusoidal-input-voltage-vin-of.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

$$2{V_m}$$

খ

$$2{V_o}\sin \omega t$$

গ

$$\sqrt 2 {V_m}$$

ঘ

$$\frac{{{V_m}}}{2}\sin \omega t$$

A half-adder is a digital circuit with

ক

three inputs and one output

খ

three inputs and two outputs

গ

two inputs and one output

ঘ

two inputs and two outputs

When an input voltage Vin, of the form shown, is applied to the circuit given below, the output voltage Vo is of the form <img src="/images/question-image/engineering-physics/electronics/1689748803-when-an-input-voltage-vin-of-the.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

খ

গ

ঘ

The feedback ratio of an amplifier, which on application of a negative feedback, changes the voltage gain from -250 to -100 is

ক

-0.250

খ

-0.025

গ

-0.060

ঘ

-0.006

Which one of the following is true for a semiconductor p-n junction with no external bias?

ক

The total charge in the junction is not conserved

খ

The p-side of the junction is positively charged

গ

The p-side of the junction is negatively charged

ঘ

No charge develops anywhere in the junction

For the rectifier circuit shown in the figure, the sinusoidal voltage (V1 or V2) at the output of the transformer has a maximum value of 10 V. The loadresistance RL, is 1 k$$\Omega $$. If lav is the average current through the resistor RL, the circuit corresponds to a <img src="/images/question-image/engineering-physics/electronics/1689747427-for-the-rectifier-circuit-shown-in-the.png" title="Electronics mcq question image" alt="Electronics mcq question image">

ক

full-wave rectifier with lav = 20/π mA

খ

half-wave rectifier with lav = 20/π mA

গ

half-wave rectifier with lav = 10/π mA

ঘ

full-wave rectifier with lav = 10/π mA