Which term best matches 'a device that measures electrical resistance'?

• A. Amp Meter
• B. Volt Meter
• C. Blueprint/Schematic
• D. Ohm Meter

Answer: (D)

Measuring resistance requires a tool that applies a known test signal and reads the response. An ohmmeter does this by supplying a small current (from its internal battery) across the component and measuring the resulting voltage, or vice versa, to calculate resistance in ohms using Ohm’s law. That’s why this instrument is used when you need to know how much a component resists current flow. Always ensure the circuit is de-energized and the part is isolated before measuring, because power on the circuit can produce inaccurate readings and pose a safety risk. An amp meter measures current (placed in series), a volt meter measures voltage (placed in parallel), and a blueprint/schematic is a drawing of connections, not a measuring device.