In a meter bridge set up, which of the following should be the properties of the one meter long wire?

Options

A. High resistivity and low temperature coefficient
B. Low resistance and low temperature coefficient
C. Low resistivity and high temperature coefficient
D. High resistivity and high temperature coefficient

Answer

To determine the properties of the one-meter long wire in a meter bridge setup, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Meter Bridge Setup**:
- A meter bridge is a device used to measure the resistance of an unknown resistor by balancing it with known resistors. The bridge consists of a one-meter long wire and a galvanometer.

2. **Properties of the Wire**:
- The wire must maintain its properties under varying conditions, such as temperature changes. This is crucial for accurate measurements.

3. **Temperature Coefficient**:
- The temperature coefficient (α) of the wire should be low. This means that the resistance of the wire should not change significantly with temperature variations. A low temperature coefficient ensures that the length of the wire remains constant, which is essential for the meter bridge to function correctly.

4. **Resistivity of the Wire**:
- The resistivity (ρ) of the wire should be high. High resistivity allows for greater sensitivity in the meter bridge. According to the formula for resistance \( R = \frac{\rho L}{A} \), if the resistivity is high, the resistance will also be high, which leads to a more significant deflection of the galvanometer for small changes in the jockey position.

5. **Conclusion**:
- Therefore, the ideal properties of the one-meter long wire in a meter bridge setup should be:
- **High resistivity**: This enhances the sensitivity of the meter bridge.
- **Low temperature coefficient**: This ensures that the resistance does not change with temperature variations.

### Final Answer:
The correct properties of the one-meter long wire in a meter bridge setup are:
- High resistivity
- Low temperature coefficient

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