If the two ends p and n of a p-n diode junction are joined by a wire, then

Options

A. there will be a steady current in the circuit
B. there will be a steady current from n-side to p-side
C. there will not be a steady current from p-side to n-side.
D. there may not be a current depending upon the resistance of the connecting wire.

Answer

To solve the question regarding the behavior of a p-n diode junction when the two ends (p-side and n-side) are joined by a wire, we can analyze the situation step by step.

### Step-by-Step Solution:

1. **Understanding the p-n Junction**: A p-n junction diode consists of two types of semiconductor materials: p-type (positive) and n-type (negative). The p-type has an abundance of holes (positive charge carriers), while the n-type has an abundance of electrons (negative charge carriers).

2. **Current Flow in a Diode**: Current in a p-n junction diode flows due to the movement of charge carriers. In forward bias (when the p-side is connected to a positive voltage), holes move from the p-side to the n-side, and electrons move from the n-side to the p-side. In reverse bias, the current is primarily due to the drift of minority carriers.

3. **Connecting the Ends with a Wire**: When the p-side and n-side of the diode are connected directly with a wire, we are effectively short-circuiting the diode. This means that there is no external voltage applied to create a potential difference across the junction.

4. **Diffusion and Drift Currents**: In the absence of an external potential difference, there will be no significant forward or reverse bias. However, there will still be some movement of charge carriers due to diffusion (movement from high concentration to low concentration) and drift (movement due to an electric field). In this case, the diffusion current (from p to n) and the drift current (from n to p) will occur simultaneously.

5. **Cancellation of Currents**: Since the diffusion and drift currents are equal in magnitude but opposite in direction, they will cancel each other out. As a result, there will be no net current flowing through the circuit.

6. **Conclusion**: Therefore, when the two ends of a p-n diode junction are joined by a wire, there will be no steady current flowing through the circuit.

### Final Answer:
The correct option is C: There may be a current depending upon the resistance of the connecting wire, but in this case, the net current will be zero due to the cancellation of diffusion and drift currents.