Question

The junction capacitance of a PN junction depends on

• A. applied voltage only
• B. barrier potential
• C. both doping concentration and applied voltage
• D. doping concentration only

Hint:

Capacitance depends on depletion width.

Answer 1

The Correct Option is C

Concept: Junction capacitance: \[ C_j \propto \frac{1}{\sqrt{V}} \]

Step 1: Dependence on voltage Increases with decrease in reverse bias.

Step 2: Dependence on doping Higher doping → thinner depletion layer → higher capacitance.

Step 3: Combined dependence Both voltage and doping affect capacitance.

Step 4: Physical interpretation Depletion width changes with both factors.

Step 5: Conclusion \[ \boxed{\text{Both doping concentration and applied voltage}} \]

Final Answer: \[ \boxed{(C)} \]