Out of following which one is a forward biased diode

Options

A.
B.
C.
D.

Answer

To determine which diode is forward biased among the given options, we need to analyze the potential of the terminals connected to the diode.

### Step-by-Step Solution:

1. **Understanding Forward Bias**:
A diode is said to be forward biased when the positive terminal of the battery is connected to the P-type side (anode) of the diode and the negative terminal is connected to the N-type side (cathode). This configuration allows current to flow through the diode.

2. **Analyzing the Options**:
We need to check the potential of each option to see if the P-side is at a higher potential than the N-side.

3. **Option 1**:
- P-side: -4V
- N-side: -2V
- Here, the N-side (-2V) is at a higher potential than the P-side (-4V). Thus, this is **not forward biased**.

4. **Option 2**:
- P-side: 2V
- N-side: 5V
- The N-side (5V) is at a higher potential than the P-side (2V). Thus, this is **not forward biased**.

5. **Option 3**:
- P-side: -2V
- N-side: +2V
- The N-side (+2V) is at a higher potential than the P-side (-2V). Thus, this is **not forward biased**.

6. **Option 4**:
- P-side: 0V
- N-side: -3V
- The P-side (0V) is at a higher potential than the N-side (-3V). Thus, this configuration allows current to flow, making it **forward biased**.

7. **Conclusion**:
The correct answer is **Option 4**, which is the forward biased diode.