Question

Diffusion current in a p-n junction is greater than the drift current in magnitude
(a) if the junction is forward-biased
(b) if the junction is reverse-biased
(c) if the junction is unbiased
(d) in no case.

Answer 1

Diffusion current in a p-n junction is greater than the drift current in magnitude, if the junction is forward-biased.

Explanation:

• When the p−n junction is forward biased, the battery’s positive terminal is linked to the p−n junction’s p side.
• The battery’s negative terminal is linked to the p−n junction’s n side. As a consequence, in the n side of the p−n junction, the electrons repel by the battery’s negative terminal and they move to the p side, where the battery’s positive terminal is attracted by the electrons.
• Likewise, on the p−n junction, holes from the p side.