If a p-n junction diode is reverse biased, then the resistance measured by an ohm-meter will be

Options

A. zero
B. low
C. high
D. infinite

Answer

To solve the question regarding the resistance measured by an ohmmeter when a p-n junction diode is reverse biased, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Reverse Bias**:
- In a p-n junction diode, when it is reverse biased, the p-side is connected to the negative terminal of the power supply and the n-side to the positive terminal. This configuration widens the depletion region and prevents significant current from flowing through the diode.

2. **Current Flow in Reverse Bias**:
- In reverse bias, the current that flows through the diode is very small, often referred to as reverse saturation current (I_r). This current is not zero but is negligible compared to the forward bias current.

3. **Resistance Calculation**:
- Resistance (R) can be calculated using Ohm's Law, which states that R = V/I, where V is the voltage across the diode and I is the current through it.
- In reverse bias, since the current (I_r) is very small, the resistance measured will be very high.

4. **Conclusion**:
- Therefore, when an ohmmeter is used to measure the resistance of a reverse-biased p-n junction diode, it will show a high resistance value, indicating that the diode is not conducting significant current.

5. **Final Answer**:
- The resistance measured by an ohmmeter will be **high**.