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 and low temperature coefficient.
B. Low resistivity 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, let's analyze the requirements step by step:

### Step 1: Understand the Purpose of the Wire
The wire in a meter bridge is used to compare the resistances of two unknown resistors. It should provide a stable and accurate measurement.

**Hint:** Consider the role of the wire in ensuring accurate resistance measurements.

### Step 2: Consider Resistivity
The wire should have a **high resistivity**. This is because a high resistivity wire will allow for a more significant voltage drop across the wire, making it easier to detect the null point when balancing the bridge.

**Hint:** Think about how resistivity affects the voltage drop across the wire.

### Step 3: Evaluate Temperature Coefficient
The wire should have a **low temperature coefficient**. This means that its resistance should not change significantly with temperature variations. A low temperature coefficient ensures that the resistance remains stable, which is crucial for accurate measurements.

**Hint:** Reflect on how temperature changes can affect resistance and the importance of stability in measurements.

### Step 4: Combine the Properties
Based on the analysis, the ideal properties for the one-meter-long wire in a meter bridge setup are:
- **High resistivity**
- **Low temperature coefficient**

### Conclusion
Therefore, the correct option is **A: High resistivity and low temperature coefficient**.

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