A multimeter is a multipurpose device that can measure _________.

• A. voltage, current, and resistance
• B. voltage and current
• C. resistance only
• D. power and energy

Answer: (A)

A multimeter is designed to measure the three fundamental electrical quantities used in circuit analysis: voltage, current, and resistance. It can read voltage by connecting across two points, measuring the potential difference without greatly loading the circuit thanks to its high input impedance. It can measure current by placing the meter in series so the circuit current flows through a known internal path, allowing the meter to sense the actual current. It can measure resistance by applying a small internal current when the circuit is unpowered and using Ohm’s law to calculate the resistance from the measured voltage and current.

Power and energy aren’t typically direct readings on a basic multimeter. Power requires multiplying voltage by current, and energy requires integrating that power over time, which most meters don’t measure directly. So the triad of voltage, current, and resistance is what a multipurpose meter is built to handle.