What device measures resistance?

What device measures resistance?

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

Answer: (A)

Measuring resistance requires a device that applies a known voltage or current and reads the response. An ohmmeter is built for this task: it has an internal power source and a current-sensing circuit, connects across the component, and shows resistance in ohms based on R = V/I. For accurate readings, the circuit should be de-energized and the component isolated, since other paths in a live circuit can skew the result. A device that measures current (an ammeter) is used in series to gauge how much current flows, not resistance. A voltmeter measures voltage and is placed in parallel to a component. A multimeter can measure resistance in its ohms setting, but the instrument specifically designed to measure resistance is the ohmmeter.

Measuring resistance requires a device that applies a known voltage or current and reads the response. An ohmmeter is built for this task: it has an internal power source and a current-sensing circuit, connects across the component, and shows resistance in ohms based on R = V/I. For accurate readings, the circuit should be de-energized and the component isolated, since other paths in a live circuit can skew the result. A device that measures current (an ammeter) is used in series to gauge how much current flows, not resistance. A voltmeter measures voltage and is placed in parallel to a component. A multimeter can measure resistance in its ohms setting, but the instrument specifically designed to measure resistance is the ohmmeter.