Concept:An ideal diode permits current to flow with zero resistance when forward-biased (closed switch) and completely blocks current with infinite resistance when reverse-biased (open switch).
Formula:$$R_{\text{ideal, reverse}} = \infty \implies I_{\text{reverse}} = 0 \quad (\text{Open Switch})$$
Solution:- In reverse bias, the depletion layer prevents majority carrier conduction.
- Because an ideal diode has zero reverse leakage current, it behaves as an open switch (infinite resistance).
Why other options are incorrect:- Option A: A short circuit represents an ideal forward-biased diode.
- Option B: A 0.7 V source represents the practical forward-biased model for silicon.
- Option C: A reverse-biased diode is passive and does not generate current.
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