Difficulty: Easy
Correct Answer: Both A and R are true and R is correct explanation of A
Explanation:
Introduction / Context:Reverse-bias characteristics of p-n junctions underpin rectification and blocking behavior in diodes. Understanding depletion layer modulation explains the high reverse resistance.
Given Data / Assumptions:
Concept / Approach:Reverse bias increases built-in potential, widens the depletion region, and lowers carrier injection, so only a tiny leakage current flows. This corresponds to a very large effective resistance.
Step-by-Step Solution:
Step 1: Reverse bias raises the barrier.Step 2: Depletion region width increases, reducing majority-carrier flow.Step 3: Leakage is limited to minority carriers; current is very small.Step 4: Hence reverse resistance is high and R explains A.Verification / Alternative check:
I-V characteristics of diodes show microampere to nanoampere reverse currents until breakdown, corroborating high resistance.Why Other Options Are Wrong:
B: R directly explains A, not merely co-occurring.C/D/E: Each contradicts standard diode theory.Common Pitfalls:
Assuming zero current under reverse bias; there is always small leakage until breakdown.Final Answer:
Both A and R are true and R is correct explanation of A
Discussion & Comments