Which device is capable of measuring voltage, current, and resistance?

• A. Multimeter
• B. Ohmmeter
• C. Ammeter
• D. Clamp meter

Answer: (A)

A device that can measure voltage, current, and resistance in one tool is designed to handle multiple basic electrical properties with separate measurement circuits inside. For voltage, the meter uses test probes across the component or power source and presents a high input impedance so it doesn’t load the circuit. For current, it is connected in series with the circuit (often via a dedicated current input or by inserting a shunt) so the meter can sense the flow and convert it to a displayable value. For resistance, the circuit is powered off, and the meter applies a small internal current and measures the resulting voltage to calculate resistance.

This makes it a versatile instrument, which is why it’s the best choice. The other devices are specialized: an ohmmeter focuses on resistance, an ammeter on current, and a clamp meter measures current (and, in some models, voltage) but does not routinely provide resistance measurement.