Using the necessary circuit diagram, show how the V-I characteristics of a p-n junction are obtained in (i) forward biasing (ii) Reverse biasing. How are these characteristics made use of in rectification?

Explanation

The circuit arrangement for studying the V–l characteristics of a diode are shown in Fig. (a) and (b). For different values of voltages the value of current is noted. A graph between V and is obtained as in Figure (c).
From the V-l characteristic of a junction diode it is clear that it allows current to pass only when it is forward biased. So if an alternating voltage is applied across a diode the current flows only in that part of the cycle when the diode is forward biased. This property is used to rectify alternating voltages.