What measurement would a clamp-on amp meter show when clamped around both wires in a two-wire circuit?

When a clamp-on amp meter is positioned around both wires in a two-wire circuit, it measures the net current flowing through the wire. In a typical situation where current is flowing out through one wire and returning through the other, the clamp-on amp meter detects the sum of the currents. Since the current flowing in one wire is equal and opposite to the current returning in the other wire, they effectively cancel each other out. This results in a measurement of zero amps.

This principle relies on the fact that the clamp-on meter works by detecting magnetic fields generated by the current flowing in the conductor. When it surrounds both conductors carrying equal currents in opposite directions, the magnetic fields also negate each other. Thus, the meter shows zero amps, indicating no net current in the circuit when clamped around both wires.