Semiconductor Electronics PYQs

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

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:

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

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

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 pn junction diode, the current measured in (μA), is due to majority charge carriers.

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

A logic circuit provides the output Y as per the following truth table. The expression for the output Y is:

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?

Given below are two statements: Statement I : Photovoltaic devices can convert optical radiation into electrical energy. 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 :

For the following logic circuit, the truth table is:

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

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

The truth table for the given logic circuit is:

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.

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.

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?

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

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

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

For the logic circuit shown, the truth table is:

An LED is constructed from a p-n junction diode using GaAsP. The energy gap is 1.9 eV. The wavelength of the light emitted will be equal to

The circuit diagram shown here corresponds to the logic gate,

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

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:

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

Which one of the following represents forward bias diode?

The given electrical network is equivalent to:

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

The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance $R_1$ will be:

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

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

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

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

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

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

In a common emitter (CE) amplifier having a voltage gain $G$, the transistor used has transconductance $0.03\,\text{mho}$ and current gain $25$. If the transistor is replaced by another one with transconductance $0.02\,\text{mho}$ and current gain $20$, the voltage gain will be

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

To get an output Y = 1 in the given circuit which of the following is correct:

The input resistance of a silicon transistor is 100 Ω. Base current is changed by 40 μA 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 kΩ. The voltage gain of the amplifier is:

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

Pure Si at 500 K has equal number of electron (nₑ) and hole (nₕ) concentrations of 1.5 × 10¹⁶ m⁻³. Doping by indium increases nₕ to 4.5 × 10²² m⁻³. The doped semiconductor is of:

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:

Two following figures show a logic gate circuit with two inputs A and B and the output Y. The voltage wave forms of A, B and Y are as given. The logic gate is

For transistor action: (1) Base, emitter and collector regions should have similar size and doping concentrations. (2) The base region must be very 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.

A p–n photodiode is fabricated from a semiconductor with a band gap of $2.5\,\text{eV}$. It can detect a signal of wavelength:

The symbolic representation of four logic gates are given below. The logic symbols for OR, NOT and NAND gates are respectively:

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

In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of

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

The circuit shown is equivalent to

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

The logic circuit shown below produces output Y. Determine the truth table and identify the equivalent logic operation.

A transistor is operated in common emitter configuration at constant collector voltage Vc = 1.5 V such that a change in the base current from 100 μA to 150 μA produces a change in the collector current from 5 mA to 10 mA. The current gain (β) is:

A forward biased diode is:

In a discharge tube ionization of enclosed gas is produced due to collisions between:

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 shown below. The logic circuit gate is:

Application of a forward bias to a p-n junction:

Zener diode is used for:

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?

Choose the only false statement from the following.