How does a clamp-on ammeter measure current?

A clamp-on ammeter measures current by utilizing the principles of electromagnetism. When an electrical current flows through a conductor, it generates a magnetic field around that wire. A clamp-on ammeter is designed to detect this magnetic field without needing to make direct contact with the wire.

The device features a sensor that can sense the magnetic field's strength, which is directly proportional to the amount of current flowing through the wire. By converting this magnetic field strength into a corresponding current reading, the ammeter provides an accurate measure of the current in the circuit.

This method of measurement is particularly advantageous because it allows for non-intrusive current measurement, meaning that the circuit does not need to be broken to take the measurement. This is why the choice about converting the magnetic field strength into an amp reading is the correct answer.

In contrast, the other options do not accurately describe the functioning of a clamp-on ammeter. Creating a voltage drop or measuring resistance applies more to other types of electrical measurement tools, while comparing potentials between two points pertains to voltmeters, not ammeters.