Which instrument can measure voltage, current, and resistance in one device?

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

Answer: (B)

Measuring multiple basic electrical parameters with a single versatile tool is the strength of a multimeter. It combines several measurement modes in one instrument, letting you switch to voltage (both AC and DC), current, and resistance. To measure voltage, you place the meter across the component so it reads the potential difference. For current, you wire it in series with the circuit so the current flows through the meter. For resistance, you typically ensure the circuit is de-energized and use the meter’s resistance mode, which sends a small current and measures the resulting voltage to compute resistance. This direct, all-in-one capability is what sets it apart from devices that only measure a single quantity. While an oscilloscope can show voltage over time and help infer behavior, it doesn’t provide a straightforward resistance reading in the same handheld form, and dedicated devices like ammeters or voltmeters only measure one parameter each.