NEETPhysicsSemiconductors
The variation of potential ( V ) with position ( x ) across a p-n junction is studied under different biasing conditions. Compared to the equilibrium state, Curve A represents a state with a higher and wider potential barrier, whereas Curve B represents a state with a lower and narrower potential barrier. Which of the following correctly identifies the biasing conditions for Curve A and Curve B?
Options
- ACurve A: Forward bias, Curve B: Reverse bias
- BCurve A: Reverse bias, Curve B: Forward bias
- CCurve A: Reverse bias, Curve B: Unbiased
- DCurve A: Unbiased, Curve B: Forward bias
Correct answer
B. Curve A: Reverse bias, Curve B: Forward bias
Step-by-step solution
In a p-n junction, applying a reverse bias increases the barrier potential and widens the depletion region. Therefore, Curve A (higher and wider barrier) corresponds to reverse bias. Applying a forward bias opposes the built-in potential, which decreases the barrier potential and narrows the depletion region. Therefore, Curve B (lower and narrower barrier) corresponds to forward bias. Answer: Curve A: Reverse bias, Curve B: Forward bias