In the figure, which of the diode is in reverse bias

Options

A.
B.
C.
D.

Answer

To determine which diode is in reverse bias, we need to analyze the voltage across the p-n junctions of the diodes in the given figure. A diode is in reverse bias when the p-side (anode) is at a lower potential than the n-side (cathode). Here’s how we can systematically approach the problem:

### Step-by-Step Solution:

1. **Identify the Diodes**:
- Let's label the diodes in the figure as A, B, C, and D for clarity.

2. **Understand Forward and Reverse Bias**:
- A diode is in **forward bias** when the p-side is at a higher potential than the n-side (P > N).
- A diode is in **reverse bias** when the p-side is at a lower potential than the n-side (P < N).

3. **Analyze Each Diode**:
- **Diode A**:
- If the p-side is positive compared to the n-side, it is forward biased.
- **Diode B**:
- If the p-side is negative compared to the n-side, it is reverse biased.
- **Diode C**:
- If the p-side is at zero volts and the n-side is at a higher voltage, it is reverse biased.
- **Diode D**:
- If the p-side is positive compared to the n-side, it is forward biased.

4. **Determine the Biasing of Each Diode**:
- For **Diode A**, if P is more positive than N, it is forward biased.
- For **Diode B**, if P is less than N, it is reverse biased.
- For **Diode C**, if P is less than N, it is reverse biased.
- For **Diode D**, if P is more positive than N, it is forward biased.

5. **Conclusion**:
- After analyzing all the diodes, we find that **Diode C** is the one that is in reverse bias because the p-side is at a lower potential compared to the n-side.

### Final Answer:
The diode that is in reverse bias is **Diode C**.

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