If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

Options

A. low resistance in parallel
B. high resistance in parallel
C. high resistance in series
D. low resistance in series.

Explanation

To solve the question of how to use an ammeter as a voltmeter, we need to follow these steps:

### Step-by-Step Solution:

1. **Understanding the Function of an Ammeter and Voltmeter**:
- An ammeter is designed to measure current and is connected in series with the circuit. It has a low internal resistance to avoid affecting the current flow.
- A voltmeter is designed to measure voltage and is connected in parallel with the component across which the voltage is to be measured. It has a high internal resistance to minimize the current drawn from the circuit.

2. **Identifying the Requirement**:
- To use an ammeter as a voltmeter, we need to modify its characteristics. Since an ammeter has low resistance, we need to increase its resistance significantly to mimic the behavior of a voltmeter.

3. **Connecting a Resistor**:
- To increase the resistance of the ammeter, we must connect a resistor in series with it. This is because connecting a resistor in series will add to the internal resistance of the ammeter, making the overall resistance higher.

4. **Choosing the Resistor**:
- The resistor that we connect in series must be of very high value. This is crucial because the voltmeter needs to have a high resistance to ensure that it does not draw significant current from the circuit.

5. **Conclusion**:
- Therefore, to use an ammeter as a voltmeter, we must connect a high resistance in series with the ammeter.

### Final Answer:
To use an ammeter in place of a voltmeter, we must connect a **high resistance in series** with the ammeter.

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