Which principle do most common meters (voltmeters, ohmmeters, ammeters) operate on?

Most common meters, such as voltmeters, ohmmeters, and ammeters, operate on the principle of electromagnetic interaction. Electromagnetic meters utilize the interaction of magnetic fields and electric currents to measure electrical quantities. For instance, in an ammeter, a current-carrying conductor generates a magnetic field that interacts with a fixed magnetic field, producing a force that moves a needle on a scale, indicating the current flowing through the circuit.

Similarly, voltmeters may employ an electromagnetic mechanism to measure voltage by sensing the current that flows through a known resistance, translating this into a voltage reading. Ohmmeters measure resistance by passing a known current through a resistor and measuring the voltage drop across it, which is also indicative of electromagnetic principles in play.

The other principles listed, such as capacitive, inductive, and resistive, either relate more to specific circuit components or behaviors rather than to the operational principle of these meters. Capacitive principles involve charge storage in capacitors, inductive principles relate to inductors and the electromagnetic induction effect, and resistive principles describe how materials oppose electric current. None of these principles universally applies to the operation of most common meters the way electromagnetic principles do.