$A$ $P-N$ junction is formed using $Si$ material. What is the approximate height of the depletion barrier in $V$?

When a $p-n$ diode is reverse biased,then

$A$ potential barrier of $0.4 \,V$ exists across a p-n junction. An electron enters the junction from the $n$-side with a speed of $6.0 \times 10^{5} \,ms^{-1}$. The speed with which the electron enters the $p$-side will be $\frac{x}{3} \times 10^{5} \,ms^{-1}$. The value of $x$ is ..............
(Given: mass of electron $= 9 \times 10^{-31} \,kg$,charge on electron $= 1.6 \times 10^{-19} \,C$.)

In a semiconductor diode,the reverse biased current is due to the drift of free electrons and holes caused by:

In the following circuits,which one of the diodes is reverse biased?

Different voltages are applied across a $P-N$ junction and the currents are measured for each value. Which of the following graphs is obtained between voltage and current?