The resistivity of a wire

Options

A. Increases with the length of the wire
B. Decreases with the area of cross-section
C. Decreases with the length and increase with the cross-section wire
D. None of the above statement is correct

Answer

To solve the question regarding the resistivity of a wire and determine which of the given statements is correct, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Resistivity**:
- Resistivity (ρ) is a property of the material of the wire. It is a measure of how strongly a material opposes the flow of electric current.

2. **Identify the Variables**:
- The resistivity of a wire is influenced by the material it is made from, not its physical dimensions (length or cross-sectional area).

3. **Analyze Each Statement**:
- **Statement A**: "The resistivity of a wire increases with the length of the wire."
- This statement is incorrect because resistivity does not depend on the length of the wire.

- **Statement B**: "The resistivity of a wire decreases with the area of cross-section."
- This statement is also incorrect. Resistivity is independent of the cross-sectional area.

- **Statement C**: "The resistivity of a wire decreases with the length and increases with the cross-section of the wire."
- This statement is incorrect as well. Resistivity does not depend on either length or cross-sectional area.

- **Statement D**: "None of the above statements is correct."
- This statement is correct because all the previous statements are false.

4. **Conclusion**:
- The correct answer is **D**: None of the above statements is correct.