Explain briefly, with the help of a circuit diagram, how V-I characteristics of a p-n junction diode are obtained in (i) forward bias, and (ii) reverse bias. Draw the shapes of the curves obtained.

(i) Forward bias:

In the forward biased condition, the p side is connected to the positive terminal and the n side is connected to the negative terminal. So, holes flow from the p side to the negative terminal and electrons flow from the n side to the positive terminal, which are the majority carriers. This results in a large amount of current with small increase in voltage.

Curve obtained:

(ii) Reverse bias :

In the reverse biased condition, the p side is connected to the negative terminal and the n side is connected to the positive terminal. So, holes flow from the n side to the negative terminal and electrons flow from the p side to the positive terminal, which are the minority carriers. This results in a small amount of current with small increase in voltage until it reaches the breakdown voltage, at which there is a huge amount of current.

Curve obtained: