When the forward bias is applied to p-n junction, it -

The correct answer is Option (2) → lowers the potential barrier

In forward bias the p-side is connected to the positive terminal of the battery. The applied voltage is opposite to the built-in potential barrier of the junction, so the barrier height falls and the depletion region becomes narrower. More majority carriers can then cross the junction, and the forward current rises.

Why the other options are incorrect

• Option (1) reduces the majority carrier current to zero — Incorrect. The majority carrier current increases in forward bias; it is in reverse bias that it is almost cut off.

• Option (3) increases the potential barrier — Incorrect. This is what reverse bias does.

• Option (4) decreases the majority carrier current — Incorrect. With a lower barrier the majority carrier current increases.

Note: A similar question was also asked in CUET (UG) 2026 on 21-05-2026 (Slot 1).

NCERT (2026-27):
p-n Junction Diode Under Forward Bias – “When an external voltage V is applied across a semiconductor diode such that p-side is connected to the positive terminal of the battery and n-side to the negative terminal [Fig. 14.13(a)], it is said to be forward biased. … The direction of the applied voltage (V) is opposite to the built-in potential V₀. As a result, the depletion layer width decreases and the barrier height is reduced [Fig. 14.13(b)].”