Correct option is C
Both statements (a) "During forward bias, the width of depletion region decreases and the barrier height is reduced" and (b) "During reverse bias, the width of depletion region increases and the barrier height increases" are correct for a p-n junction diode.
Explanation:
Forward bias:
When a p-n junction is forward biased, the positive terminal of the power source is connected to the p-side and the negative side to the n-side. This applied voltage opposes the built-in potential barrier, causing the depletion region to narrow and reducing the barrier height.
Reverse bias:
In reverse bias, the p-side is connected to the negative terminal and the n-side to the positive terminal. This applied voltage enhances the built-in potential barrier, resulting in an increase in the width of the depletion region and a higher barrier height.
Depletion region:
This is a region near the junction of p-type and n-type semiconductors where the mobile charge carriers have been depleted due to diffusion.
Barrier potential:
This is the potential difference across the depletion region, which prevents the majority carriers from easily crossing the junction.
