What is a rectifier explain the working of P-N diode as half wave rectifier

Explanation

p-n junction as half wave rectifier
The circuit for using junction diode as half wave rectifier is as shown below in figure (a) .

During first half of a.c.one of the ends of secondary say A ,becomes positive and diode operates under forward bias and the current flows through load R. During second half, A becomes negative and diode operates under negative bias. Practically no current flows through the load. Thus half of the cycle of a.c. is rectified and we get unidirectional current as shown in fig. (b).