Which device should be connected in parallel to measure the voltage across a component?

Which device should be connected in parallel to measure the voltage across a component?

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

Answer: (A)

To measure the voltage across a component, you connect the measuring device in parallel with that component. This setup ensures the same voltage appears across both and, because the voltmeter is designed to draw very little current, it doesn’t disturb the circuit’s operation. The device that fits this purpose is a voltmeter, which has a high internal resistance to minimize current draw. An ammeter, by contrast, is meant to measure current and is placed in series; placing it in parallel would disrupt the circuit because it presents a much lower resistance and can create a short. A multimeter can measure voltage when set to the voltage function, and in that mode it acts as a voltmeter and should be connected in parallel; however, it’s a multifunction tool rather than a dedicated voltage-measuring instrument. A barometer measures atmospheric pressure, not electrical quantities, so it isn’t used for voltage measurement. So, for measuring the voltage across a component, use the voltmeter.

To measure the voltage across a component, you connect the measuring device in parallel with that component. This setup ensures the same voltage appears across both and, because the voltmeter is designed to draw very little current, it doesn’t disturb the circuit’s operation.

The device that fits this purpose is a voltmeter, which has a high internal resistance to minimize current draw. An ammeter, by contrast, is meant to measure current and is placed in series; placing it in parallel would disrupt the circuit because it presents a much lower resistance and can create a short. A multimeter can measure voltage when set to the voltage function, and in that mode it acts as a voltmeter and should be connected in parallel; however, it’s a multifunction tool rather than a dedicated voltage-measuring instrument. A barometer measures atmospheric pressure, not electrical quantities, so it isn’t used for voltage measurement.

So, for measuring the voltage across a component, use the voltmeter.