Question Detail
Question
Which of the following is true about p-n junction diode?
i. Forward bias current rises linearly.
ii. Reverse bias current is absolutely zero.
iii. Width of depletion region is unchanged when forward biased.
i. Forward bias current rises linearly.
ii. Reverse bias current is absolutely zero.
iii. Width of depletion region is unchanged when forward biased.
Correct Answer
Option D is the correct answer.
Detailed Explanation
Let's analyze each statement:i. Forward bias current rises exponentially, not linearly, after the knee voltage. In practical circuits, a series resistor might make it appear linear above the knee voltage, but the diode characteristic itself is exponential.ii. Reverse bias current is not absolutely zero. There is a small reverse saturation (leakage) current due to minority carriers, and at higher reverse voltages, breakdown occurs.iii. The width of the depletion region decreases when a p-n junction diode is forward biased, as the applied voltage opposes the built-in potential, reducing the effective potential barrier.Since all three statements are false, the correct option is 'none'.
Hint
Recall the characteristics of a p-n junction diode under forward and reverse bias conditions, especially how current changes and how the depletion region is affected.