In an electrical circuit, which instrument is not typically used to measure current?

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

Answer: (D)

Measuring current requires an instrument that becomes part of the circuit path, allowing the same current to flow through it with minimal disruption. An ammeter is built for this: it’s placed in series and has very low resistance so it doesn’t significantly alter the circuit. A multimeter can also measure current when set to the current mode, effectively acting as a series element. An ohmmeter is used to determine resistance by applying a small internal current and reading the response, typically with the component isolated from live circuits.

The voltmeter, by contrast, is designed to measure voltage and is connected in parallel across a component. It has a high internal resistance to avoid drawing current from the circuit. If you tried to use a voltmeter to measure current, its large resistance would prevent most of the current from flowing through it, yielding an incorrect or meaningless current reading. Therefore, the instrument not typically used to measure current is the voltmeter.