$A$ semiconductor $(Ge - As)$ has an energy gap of $1.43\, eV.$ What is the maximum wavelength emitted when a hole and an electron recombine in such semiconductor in $\mathring{A}$?

The diode used in the circuit shown in the figure has a constant voltage drop of $0.5\; V$ at all currents and a maximum power rating of $100\; mW$. What should be the value of the resistor $R$,connected in series with the diode,to obtain the maximum current? (in $\Omega$)

The circuit shown contains a $12 \, V$ battery,a $4 \, \Omega$ resistor,and two branches in parallel,each containing an ideal diode and a resistor. Branch $1$ has diode $D_1$ and a $3 \, \Omega$ resistor,while branch $2$ has diode $D_2$ and a $2 \, \Omega$ resistor. Determine the current flowing through the circuit. (in $, A$)

If the forward voltage in a semiconductor diode is doubled,the width of the depletion layer will

The current $I$ through the $10\, \Omega$ resistor in the given circuit is.......$mA$.

The diode shown in the circuit is a silicon diode. The potential difference between the points $A$ and $B$ will be.....$V$