A potentiometer is an ideal device of measuring potential difference because

Options

A. it uses a sensitive galvanometer
B. it does not disturb the potential difference it measures
C. it is an elaborate arrangement
D. it has a long wire hence heat developed quickly radiated

Answer

To solve the question "A potentiometer is an ideal device of measuring potential difference because," we need to analyze the options provided and determine which one correctly describes the advantages of a potentiometer over other measuring devices like a voltmeter.

### Step-by-Step Solution:

1. **Understanding the Potentiometer**:
- A potentiometer is a device used to measure the potential difference (voltage) across two points in a circuit without drawing any current from the circuit being measured. This is crucial because drawing current can alter the voltage being measured.

2. **Analyzing Option 1**:
- **It uses a sensitive galvanometer**:
- While it is true that a potentiometer uses a galvanometer, this is not a unique advantage. A voltmeter also uses a galvanometer. Therefore, this option does not explain why a potentiometer is ideal for measuring potential difference.

3. **Analyzing Option 2**:
- **It does not disturb the potential difference it measures**:
- This is a key advantage of the potentiometer. When measuring voltage, the potentiometer does not draw current from the circuit, thus it does not affect the potential difference across the component being measured. This makes it an ideal device for measuring potential difference accurately.

4. **Analyzing Option 3**:
- **It is an elaborate arrangement**:
- While a potentiometer setup may be more complex than simply using a voltmeter, this does not contribute to its effectiveness in measuring potential difference. Therefore, this option does not support the claim.

5. **Analyzing Option 4**:
- **It has long wire hence heat developed quickly radiated**:
- While it is true that a long wire can increase the sensitivity of the potentiometer, the statement about heat radiation is misleading. The length of the wire is not primarily for heat dissipation but for increasing sensitivity. Thus, this option is not correct.

6. **Conclusion**:
- After analyzing all options, the correct answer is that a potentiometer is an ideal device for measuring potential difference because it does not disturb the potential difference it measures (Option 2).

### Final Answer:
A potentiometer is an ideal device of measuring potential difference because it does not disturb the potential difference it measures.