Semiconductors Questions

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

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

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 $300\mu \text{A}$ produces a change in the collector current from $10\text{mA}$ to $20\text{mA}$. The current gain is:

If a small amount of antimony is added to germanium crystal:

In forward biasing of the $p$ -$n$ junction:

Symbolic representation of four logic gates are shown as:(i) OR gate AND gate NOT gate [NAND gate]Pick out which ones are for AND, NAND and NOT gates, respectively:

A Zener diode with $V_Z=15\text{V}$ is used in a regulator with $V_{in}=20\text{V}$ and $R_s=250\Omega ,R_L=1\text{k}\Omega$. Current through diode is:

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

In which of the following figures are the diodes forward biased?

Pure $\text{Si}$ at $500\text{K}$ has $n_i=1.5\times 10^{16}{\text{m}}^{-3}$. Doping by Indium increases $n_h$ to $4.5\times 10^{22}{\text{m}}^{-3}$. The doped semiconductor is:

To get an output $Y=1$ in the given circuit (AND gate with inputs $A,B$ and then OR gate with $C$), which of the following input will be correct:

Silicon transistor input resistance is $100\Omega$. Base current changes by $40\mu \text{A}$ resulting in collector current change of $2\text{mA}$. For a load resistance of $4\text{k}\Omega$ in common emitter, voltage gain is:

$C$ 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:

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

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:

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

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

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 drop across it is $0.8\text{V}$. 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:

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:

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

Consider an $n$ -$p$ -$n$ transistor amplifier in common-emitter configuration. The current gain of the transistor is $100$. If the collector current changes by $1\text{mA}$, what will be the change in emitter current?

In a semiconducting material the mobilities of electrons and holes are ${\mu }_e$ and ${\mu }_h$ respectively. Which of the following is true?

Assertion: The logic gate NOT can be built using diode.Reason: The output voltage and the input voltage of the diode have $180^{\circ }$ phase difference.

Assertion: The number of electrons in a $p$ -type silicon semiconductor is less than the number of electrons in a pure silicon semiconductor at room temperature.Reason: It is due to law of mass action.

Assertion: In a common emitter transistor amplifier the input current is much less than the output current.Reason: The common emitter transistor amplifier has very high input impedance.

A transistor-oscillator using a resonant circuit with an inductance $L$ (of negligible resistance) and a capacitance $C$ has a frequency $f$. If $L$ is doubled and $C$ is changed to $4C$, the frequency will be:

A transistor is operated in common emitter configuration at constant collector voltage $V_c=1.5\text{V}$ such that a change in the base current from $100\mu \text{A}$ to $150\mu \text{A}$ produces a change in the collector current from $5\text{mA}$ to $10\text{mA}$. The current gain ($\beta$) is:

Which of the following is an example of forward biasing?

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 as shown below:(Assuming waveforms where C is high only when both A and B are high, matching a standard AND gate profile)The logic circuit gate is :

Which of the following statements is False?

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:

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:

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 $2.0\text{eV}$. The minimum frequency of the radiation that can be absorbed by the material is nearly:

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

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:

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: