How is a voltmeter connected in a circuit to measure the potential difference across a component?

Correct Option

The correct option is In parallel.

Explanation

A voltmeter is an electrical instrument used to measure the potential difference (voltage) between two points in an electric circuit. The method of connection is governed by the requirement to measure the voltage drop across a specific component without altering the current flowing through the circuit.

Analysis of Connection:

• Parallel Connection: To measure the potential difference across a component (such as a resistor or a bulb), the voltmeter must be connected to the same two points as the component. This is a parallel connection. In this configuration, the potential difference across the voltmeter is identical to the potential difference across the component.
• Resistance Requirement: A voltmeter is designed with very high internal resistance. When connected in parallel, this high resistance ensures that the meter draws negligible current from the main circuit. Consequently, the circuit's total current and the voltage drop across the component remain practically unchanged.
• Contrast with Series Connection: If a voltmeter were connected in series, its high resistance would drastically reduce the total current in the circuit, leading to a malfunction of the circuit and an incorrect reading of the potential difference across the component.

Key Takeaway:
A voltmeter is always connected in parallel to the component being measured and possesses high resistance. In contrast, an ammeter is connected in series and has low resistance.