What is measured by a wattmeter?

A wattmeter is designed to measure the electrical power consumed in a circuit, which is quantified in watts. This device provides important information regarding how much energy is being used over time, making it invaluable for determining energy efficiency and understanding the operation of electrical systems.

When a wattmeter is connected to a circuit, it measures both the voltage across the circuit and the current flowing through it. The power consumed is then calculated by multiplying these two factors (P = VI), considering the phase difference between voltage and current in AC systems, thus accounting for the power factor.

This is a fundamental concept in electrical engineering and practical applications, where knowing the amount of electrical power consumed helps in designing systems, energy billing, and managing loads in electrical networks. Understanding this function is essential for anyone studying electric systems and looking to apply that knowledge practically.