Embibe Experts Solutions for Chapter: Semiconductors and Their Applications, Exercise 2: Exercise 2

The electrical conductivity of a semiconductor increases when electromagnetic radiation of a wavelength shorter than $2480 \mathrm{nm}$ is incident on it. Find the band gap of the semiconductor. [Given $h=6.63\times {10}^{-34}\mathrm{J} \mathrm{s}\text{, }c=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$]

Find the current flowing through the $1 \mathrm{k\Omega }$ resistor shown in the figure. 

In the circuit shown below, the voltage across the $2 \mathrm{k\Omega }$ resistor is 

The resistance of a germanium junction diode whose $V-I$ is shown in the figure is $\left(V_k=0.3 \mathrm{V}\right)$

The circuit shown in the figure contains two diodes each with a forward resistance of $50 \mathrm{\Omega }$ and with infinite reverse resistance. If the battery voltage is $6 \mathrm{V}$, find the current through the $100 \mathrm{\Omega }$ resistance.

The barrier potential of a silicon diode is $0.7 \mathrm{V}$ at $25°\mathrm{C}$. Find the barrier potential at $-20°\mathrm{C}$ and at $110°\mathrm{C}$.

Two identical $P$ - $N$ junction may be connected in series with a battery in three ways (figure). The potential drops across the two $P$ -$N$ junction are equal in- 

The input resistance of a common emitter amplifier is $330 \mathrm{\Omega }$ and the load resistance is $5 \mathrm{k\Omega }$ . A change of base current is $15 \mathrm{\mu A}$ results in the change of collector current by $1 \mathrm{mA}$ . The voltage gain of the amplifier is