Question

Diode is forward biased and the applied voltage is greater that the potential barrier then
I) resistance of the junction in the forward bias decreases.
II) potential barrier remains same.
III) width barrier remains decreases.
IV) p-type is at higher potential than the n-type.

• A. all are true
• B. all are false
• C. I, III, IV are true
• D. I, II, III are true

Answer 1

The correct option is C I, III, IV are true

In forward bias condition, the positive terminal of battery is connected to the p-type and the negative terminal of battery is connected to the n-type, i.e., p-type is at higher potential than n-type.
When the applied potential is more than barrier potential, the charge carriers, i.e., the holes in the p-type region and the electrons in the n-type region are pushed toward the junction. This reduces the width of the depletion region.
With increasing forward-bias voltage, the depletion region eventually becomes thin enough that the it's electric field cannot counteract charge carrier motion across the p-n junction, as a consequence reducing electrical resistance.