What is the product of the readings of an AC voltmeter and AC ammeter called?

The product of the readings of an AC voltmeter and an AC ammeter is referred to as apparent power. This term arises from the way power is measured in alternating current (AC) circuits. Apparent power is quantified in volt-amperes (VA) and represents the combination of both real power (which performs useful work) and reactive power (which sustains the electric and magnetic fields in the system).

In AC circuits, the voltage and current can be out of phase due to the presence of reactive components such as inductors and capacitors. As a result, the straightforward multiplication of voltage and current does not yield the true power that performs work in the circuit; rather, it provides a measure of the total power. This is why it's called "apparent" power, as it appears to be the total power flowing in the circuit, even though it doesn't entirely correspond to the power used effectively.

Understanding apparent power is crucial for evaluating how much power is being supplied and managing the efficiency of electrical systems, especially in industries that utilize various AC loads.