Semiconductor Devices and Logic Gates

Practice Questions

MCQ (Single Correct Answer)

In the diodes show in the diagrams, which one is reverse biased?

AP EAPCET 2024 - 23th May Morning Shift

$$ \text { The following configuration of gates is equivalent to } $$

AP EAPCET 2024 - 23th May Morning Shift

$$ \text { Truth table for the given circuit is } $$

AP EAPCET 2024 - 22th May Evening Shift

If $R_C$ and $R_B$ are respectively the resistances of in collector and base sides of the circuit and $\beta$ is the current amplification factor, then the voltage gain of a transistor amplifier in common emitter configuration is

AP EAPCET 2024 - 22th May Evening Shift

The current gain of a transistor in common emitter configuration is 80 . The resistances in collector andbase sides of the circuit are $5 \mathrm{k} \Omega$ and $1 \mathrm{k} \Omega$ respectively. If the input voltage is 2 mV , the output voltage is

AP EAPCET 2024 - 22th May Morning Shift

Four logic gates are connected as shown in the figure. If the inputs are $A=0, B=1$ and $C=1$, then the values of $Y_1$ and $Y_2$ respectively, are

AP EAPCET 2024 - 22th May Morning Shift

Pure silicon at 300 K has equal electron and hole concentration of $1.5 \times 10^{16} \mathrm{~m}^{-3}$. If the hole concentration increases to $3 \times 10^{22} \mathrm{~m}^{-3}$, then electron concentration in the silicon is

AP EAPCET 2024 - 21th May Evening Shift

In $n-p-n$ transistor circuit, the collector current is 10 mA . If $95 \%$ of the electrons emitted reach the collector, then the base current is nearly

AP EAPCET 2024 - 21th May Evening Shift

The semiconductor used for fabrication of visible LEDS must at least have a band gap of

AP EAPCET 2024 - 21th May Morning Shift

In a common emitter amplifier, AC current gains 40 and input resistance is $2 \mathrm{k} \Omega$. The load resistance is given as $10 \mathrm{k} \Omega$. Then, the voltage gain is

AP EAPCET 2024 - 21th May Morning Shift

The voltage gain and current gain of a transistor amplifier in common emitter configuration are respectively 150 and 50 . If the resistance in the base circuit is $850 \Omega$, then the resistance in collector circuit is

AP EAPCET 2024 - 20th May Evening Shift

If the energy gap of a substance is 5.4 eV , then the substance is

AP EAPCET 2024 - 20th May Evening Shift

A p-n junction diode is used as

AP EAPCET 2024 - 20th May Morning Shift

When a signal is applied to the input of a transistor, it was found that output signal is phase-shifted by $180^{\circ}$. The transistor configuration is

AP EAPCET 2024 - 19th May Evening Shift

If $n_r$ and $n_h$ are concentrations of electron and holes in a semiconductor, then the intrinsic carrier concentration $n_j$ in thermal equilibrium is

AP EAPCET 2024 - 18th May Morning Shift

In the given digital circuit, if the inputs are $A=1 B_x$ and $C=1$, then the value of $Y_1$ and $Y_2$ are respectino

AP EAPCET 2024 - 18th May Morning Shift

Consider the statements In a semiconductor

(A) There are no free electrons at 0 K.

(B) There are no free electrons at any temperature.

(D) The number of free electrons is less than that in a conductor.

AP EAPCET 2022 - 4th July Evening Shift

Output of following logic circuit is

AP EAPCET 2022 - 4th July Morning Shift

The truth table given below corresponds to logic gate.

AP EAPCET 2021 - 20th August Morning Shift

A transistor is connected in common emitter configuration. The collector supply is $$8 \mathrm{~V}$$ and the voltage drop across a resistor of $$800 \Omega$$ in the collector circuit is $$0.5 \mathrm{~V}$$. If the current gain factor $$\alpha$$ is 0.96, then the base current is

AP EAPCET 2021 - 19th August Morning Shift