If the two ends $P$ and $N$ of a $P-N$ junction diode are joined by a wire,what happens?

Write a short note on a semiconductor diode.

In the case of forward biasing of a $PN-$ junction,which one of the following figures correctly depicts the direction of flow of majority charge carriers?

The $I-V$ characteristic of a $p-n$ junction diode is shown in the figure. Find the approximate dynamic resistance of the $p-n$ junction when a forward bias of $1 \text{ V}$ is applied. (in $\Omega$)

$A$ 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 forward voltage is increased from $0.5 \ V$ to $0.7 \ V$. As a result,the forward current changes by $1 \ mA$. The forward resistance of the diode is ....... $\Omega$.