NABCEP Technical Sales Practice Exam

The quantity of electricity used is best represented by the formula that multiplies power by time. In electrical contexts, power (measured in watts) indicates how much energy is consumed per unit of time. When you multiply power by the duration of time the power is used, you obtain energy consumption, typically measured in watt-hours (Wh) or kilowatt-hours (kWh).

This relationship is crucial in understanding energy usage, as it highlights that both the level of power and the length of time it is used contribute significantly to the total electricity consumed. For instance, if you run a 1000-watt appliance for 2 hours, the energy consumed would be calculated as 1000 watts multiplied by 2 hours, resulting in 2000 watt-hours or 2 kilowatt-hours. This direct multiplication reflects the accumulated energy over the specified time period, solidifying why the appropriate formula incorporates both elements in this manner.