Draw a circuit diagram of a $p$-$n$ junction under reverse bias, using proper symbol for diode (not rectangular block).

Draw $V$-$I$ characteristic curve for a $p$-$n$ junction diode. Show the Zener voltage on the curve.

Draw a labelled circuit diagram of a full-wave rectifier using $p$-$n$ junction diodes.

An $n$-type semiconductor has excess of free electrons, while a $p$-type semiconductor has a deficiency of these. But when a $p$-$n$ junction is formed, all the electrons do not flow from the $n$-region to the $p$-region. Why?

Indicate which of the following $p$-$n$ diodes are forward biased and which are reverse biased: