Which device can function as an ohmmeter, ammeter, or voltmeter when configured accordingly?

• A. Megger.
• B. Multimeter.
• C. Oscilloscope.
• D. Grounding strap.

Answer: (B)

A multimeter is designed to switch between measuring resistance, current, and voltage, using different settings and test leads. When set to resistance and with the circuit de-energized, it injects a small current and measures the resulting voltage drop to display ohms. When set to current and placed in series with the circuit, it uses a built-in shunt to measure the flow of current, acting like an ammeter. When set to voltage, the probes are placed across a component or source to read the potential difference, functioning as a voltmeter. This versatility is why it’s the best fit for all three measurements. The other devices have different primary roles: a megger tests insulation resistance at high voltage, not general-purpose ohmmeter/ameter/voltmeter functions; an oscilloscope shows voltage waveforms and can measure voltage with its probes but isn’t used as a basic ammeter or ohmmeter by default; a grounding strap is a safety tool and does not measure electrical values.