Question

In a reversed-biased p-n junction diode, the applied voltage mostly drops across ______.

Options

• p-region only

• n-region only

• depletion region

• the diode

Answer 1

In a reversed-biased p-n junction diode, the applied voltage mostly drops across depletion region.

Explanation:

When the battery is in reverse bias, the n-side is connected to the positive terminal and the p-side to the negative terminal. The depletion region is expanded as a result.

The depletion region is devoid of mobile charge carriers (electrons and holes).

As a result of this, the depletion region's resistance is much higher than that of the doped semiconductors’ p and n regions.

According to Ohm’s law and potential divider logic, in a series arrangement, the largest potential drop occurs across the highest resistance.

Therefore, almost the entire applied external voltage drops across the depletion region.