Question

In the depletion region of a diode ______.

1. there are no mobile charges.
2. equal number of holes and electrons exist, making the region neutral.
3. recombination of holes and electrons has taken place.
4. immobile charged ions exist.

विकल्प

• a and b

• a, b and d

• c and d

• a, b, c and d

Answer 1

a, b, c and d

Explanation:

On account of the difference in concentration of charge carrier in the two sections of the P-N junction, the electrons from N-region diffuse through the junction into P-region and the hole from P-region diffuse into N-region.

Due to diffusion, the neutrality of both N and P-type semiconductor is disturbed, a layer of negatively charged ions appear near the junction in the P-crystal and a layer of positive ions appears near the junction in N-crystal. This layer is called the depletion layer.

The thickness of the depletion layer is 1 micron = 10^-6 m.
Width of depletion layer ∞ 1/Dopping

Depletion is directly proportional to temperature.

Important point: The P-N junction diode is equivalent to the capacitor in which the depletion layer acts as a dielectric.