Explain with a neat diagram, how a p-n junction diode is used as a half wave rectifier.

Explanation

Rectifier is a device which converts ac voltage into dc voltage. It produces unidirectional and pulsating voltage from ac source which is provided by the transformer across secondary windings. Half wave rectifier is an electronic circuit which converts half cycle of a.c. voltage in d.c. voltage. The p-n junction diode (D) is connected in series with load resistance `R_(L)`.
In the positive half cycle, point A becomes positive w.r.t point B and diode D will be forward biased and conduct i.e., current flows through `R_(L)` from A to B.
However, during the negative half cycle i.e., when point A becomes negative w.r.t. point B, diode D is reverse biased and it does not conduct i.e., no current flows through `R_(L)`.
Since p-n junction diode conducts only in one-half cycle of the sine wave, hence it is used as a half-wave rectifier.