The resistance of p-n junction is low when forward biased and is high when reverse biased. Explain.

Explanation

When p-n junction is forward biased, the width of depletion layer decreases and the barrier potential is opposed by the forward bias, In other words, potential barrier decreases.Hence the diffusion of holes and electrons through the junction increases. Due to this, the diode current increases and hence resistance decreases, When p-n junction is reverse biased, the barrier potential is supported and width of depletion layer increases. As a result of this the diode current becomes almost zero as there is no diffision of majority carriers (electrons and holes) through the junction. Hence the resistance of the junction diode increases when reverse biased.