The net resistance of a volmeter should be large to ensure that

Options

A. (a)it does not get overheated
B. (b)it does not draw excessive current
C. (c )it can measure large potential defferences
D. (d)it does not apperciably change the potential difference to be measured.

Answer

To solve the question regarding why the net resistance of a voltmeter should be large, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Function of a Voltmeter**:
- A voltmeter is an instrument used to measure the potential difference (voltage) between two points in an electrical circuit.

2. **Connection of Voltmeter in a Circuit**:
- A voltmeter is connected in parallel with the component (like a resistor) across which the voltage is to be measured. This is essential because it allows the voltmeter to measure the voltage drop across that component without significantly affecting the circuit.

3. **Effect of Voltmeter Resistance**:
- The resistance of the voltmeter must be very high. This is because if the voltmeter has low resistance, it will draw a significant amount of current from the circuit. This can lead to a situation where the voltmeter itself alters the current flowing through the circuit, thereby affecting the voltage reading.

4. **Ensuring Accurate Measurement**:
- By having a high resistance, the voltmeter draws negligible current. This ensures that most of the current in the circuit flows through the main branch (the component being measured), allowing for an accurate measurement of the potential difference across the terminals.

5. **Conclusion**:
- Therefore, the net resistance of a voltmeter should be large to ensure that it does not affect the circuit operation and provides an accurate measurement of the voltage across the component.

### Final Answer:
The net resistance of a voltmeter should be large to ensure that it draws negligible current, allowing for an accurate measurement of the potential difference across the component without significantly affecting the circuit.

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