In the middle of the depletion layer of a reverse - biased `p - n ` junction , the

Options

A. electron field is zero
B. potential is maximum
C. electron field is maximum
D. potential is zero

Explanation

To solve the question regarding the characteristics of the depletion layer in a reverse-biased p-n junction, we need to analyze the behavior of the electric field, potential, and charge carriers in this configuration.

### Step-by-Step Solution:

1. **Understanding Reverse Bias**:
In a reverse-biased p-n junction, the positive terminal of the battery is connected to the n-type semiconductor, and the negative terminal is connected to the p-type semiconductor. This setup widens the depletion region as it pulls majority carriers away from the junction.

**Hint**: Remember that in reverse bias, the junction is designed to block current flow.

2. **Depletion Region**:
The depletion layer is the region around the p-n junction where charge carriers (holes in p-type and electrons in n-type) are depleted. This region is devoid of free charge carriers, leading to the formation of an electric field.

**Hint**: Focus on the concept of charge carriers being pulled away from the junction.

3. **Electric Field in the Depletion Layer**:
In the depletion region, there is an electric field directed from the n-type side to the p-type side. This electric field is maximum at the edges of the depletion region and decreases towards the center.

**Hint**: The electric field is influenced by the charge distribution in the depletion region.

4. **Potential in the Depletion Layer**:
The electric potential is maximum at the center of the depletion layer. As you move away from the center towards either side (n-type or p-type), the potential decreases.

**Hint**: Remember that potential is related to the work done against the electric field.

5. **Behavior of Charge Carriers**:
In the depletion region, the concentration of charge carriers is very low, and thus, the electric field is strong. However, the potential barrier is at its maximum in the middle of the depletion layer.

**Hint**: Consider how the potential barrier affects the movement of charge carriers.

6. **Conclusion**:
In summary, in the middle of the depletion layer of a reverse-biased p-n junction:
- The electric field is maximum.
- The potential is maximum.
- The concentration of charge carriers (electrons and holes) is at its minimum.

### Final Answer:
In the middle of the depletion layer of a reverse-biased p-n junction, the electric field is maximum, and the potential is also maximum.