Which of the following is a non metallic conductor

Options

A. Diode
B. Transistor
C. Solar cell
D. All of these

Answer

To determine which of the following is a non-metallic conductor, we will analyze the options provided.

### Step-by-Step Solution:

1. **Understanding Conductors**:
- Conductors are materials that allow the flow of electric current. They can be metallic or non-metallic. Metallic conductors include metals like copper and aluminum, while non-metallic conductors include materials like semiconductors.

2. **Identifying the Options**:
- The options given are:
- Diode
- Transistor
- Solar Cell
- All of the above

3. **Analyzing Each Option**:
- **Diode**: A diode is made from semiconductor materials, specifically from P-type and N-type semiconductors. Therefore, it is a non-metallic conductor.
- **Transistor**: Similar to diodes, transistors are also made from semiconductor materials. They can be configured as PNP or NPN, which also makes them non-metallic conductors.
- **Solar Cell**: A solar cell functions on the principle of semiconductor physics and is made from semiconductor materials as well. Thus, it is also a non-metallic conductor.

4. **Conclusion**:
- Since all the options (diode, transistor, and solar cell) are made from semiconductor materials, they all qualify as non-metallic conductors. Therefore, the correct answer is **option number 4: All of the above**.