The approximate ratio of resistances in the forward and reverse bias of the $PN$-junction diode is

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 carriers?

$A$ circuit and the signal applied at its input terminal $(V_i)$ are shown in the figure below. Which one of the options correctly describes the output waveform $(V_0)$? (Assume all the devices used are ideal and take $P$ as the reference potential.)

Two identical $P-N$ junctions are connected in series with a battery in three ways as shown in the figure. In which two circuits will the potential difference across the $P-N$ junctions be equal?

When a forward bias is applied to a $p-n$ junction,it $\qquad$ .