Choose the correct option for the forward biased characteristics of a p-n junction

Options

A.
B.
C.
D.

Answer

To solve the question regarding the forward-biased characteristics of a p-n junction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Forward Biasing**:
- In a p-n junction diode, forward biasing occurs when the positive terminal of the battery is connected to the p-type material (anode) and the negative terminal is connected to the n-type material (cathode). This reduces the barrier potential and allows current to flow.

2. **Current-Voltage Relationship**:
- In forward bias, a small increase in voltage results in a large increase in current. This is due to the exponential relationship described by the diode equation:
\[ I = I_0 (e^{\frac{qV}{kT}} - 1) \]
- Here, \(I_0\) is the reverse saturation current, \(q\) is the charge of an electron, \(V\) is the voltage across the diode, \(k\) is Boltzmann's constant, and \(T\) is the absolute temperature.

3. **Analyzing Graphs**:
- We need to analyze the given options (graphs) to find one that represents the forward bias characteristics correctly.
- The correct graph should show that a small increase in voltage leads to a significant increase in current.

4. **Evaluating Each Graph**:
- **Graph 1**: Shows a linear increase in current with voltage. This is incorrect because it does not reflect the exponential increase in current with a small increase in voltage.
- **Graph 2**: Shows current decreasing after a certain point, which is also incorrect for forward bias.
- **Graph 3**: Displays a curve where a small increase in voltage results in a large increase in current, which aligns with the expected behavior of a forward-biased diode.
- **Graph 4**: Shows a large increase in voltage for a small increase in current, which contradicts the forward bias characteristics.

5. **Conclusion**:
- Based on the analysis, **Graph 3** is the correct option as it accurately represents the forward-biased characteristics of a p-n junction diode.

### Final Answer:
The correct option for the forward-biased characteristics of a p-n junction is **Graph 3**.