What does the electric meter on a house measure?

The electric meter on a house primarily measures the amount of electrical energy consumed over time, which is often expressed in kilowatt-hours (kWh). While wattage, current, and voltage are all important electrical concepts, the electric meter itself is designed to specifically track the total energy usage rather than these individual elements.

When considering wattage, it is important to recognize that it is a measure of the rate of energy consumption. To measure wattage, one would typically calculate the product of voltage and current (using the formula P = VI). However, the meter provides a cumulative reading of the energy consumed in kilowatt-hours, thus primarily focusing on total energy usage.

The other options—current, voltage, and power factor—are fundamental electrical parameters, which can be measured using different tools such as ammeters or voltmeters, but they do not represent the full picture of energy consumption as conveyed by the electric meter. Therefore, wattage serves as a representation of the energy consumed, making it the correct context in this scenario.