Which device is connected across components to measure the potential difference?

Which device is connected across components to measure the potential difference?

• A. Voltmeter
• B. Ammeter
• C. Ohmmeter
• D. Multimeter

Answer: (A)

Measuring potential difference means comparing the electrical energy between two points, so you connect the measuring device across those points. A voltmeter is designed for this task: it has very high input resistance, so it draws almost no current and doesn’t disturb the circuit, yet it reads the voltage difference directly across the component. That parallel connection is what lets you see the potential difference cleanly, whether you’re measuring across a resistor, a battery, or any two points in a circuit. In contrast, an ammeter must be placed in series to measure current, because it needs to measure the flow of charge through a path. An ohmmeter measures resistance by applying a small current, usually when the circuit is unpowered. A multimeter can measure voltage, current, and resistance, but when you’re specifically measuring potential difference, the important detail is connecting it in parallel so it reads the voltage without altering the circuit.

Measuring potential difference means comparing the electrical energy between two points, so you connect the measuring device across those points. A voltmeter is designed for this task: it has very high input resistance, so it draws almost no current and doesn’t disturb the circuit, yet it reads the voltage difference directly across the component. That parallel connection is what lets you see the potential difference cleanly, whether you’re measuring across a resistor, a battery, or any two points in a circuit.

In contrast, an ammeter must be placed in series to measure current, because it needs to measure the flow of charge through a path. An ohmmeter measures resistance by applying a small current, usually when the circuit is unpowered. A multimeter can measure voltage, current, and resistance, but when you’re specifically measuring potential difference, the important detail is connecting it in parallel so it reads the voltage without altering the circuit.