question_answer

  Application of a forward bias to a \[p-n\]  junction:                                                  [AIPMT (S) 2005]

A)        increases the number of donors on the n-side

B)       increases the electric field in the depletion zone

C)       increases the potential difference across the depletion zone

D)       widens the depletion zone

Correct Answer: A

Solution :

When p-side of junction diode is connected to positive of battery and n-side to the negative, then junction diode is forward biased.

In this condition, more number of electrons enter in n-side from battery thereby increasing the number of donor on n-side.

Note:    The curves for charge density, electric field and potential barrier for a \[p-n\] junction are as shown in figure below: