What is the formula for calculating energy consumed in kilowatt-hours?

• A. Energy (kWh) = Power (W) x Time (s)
• B. Energy (kWh) = Power (kW) x Time (h)
• C. Energy (kWh) = Power (V) x Time (h)
• D. Energy (kWh) = Power (A) x Time (h)

Answer: (B)

The correct formula for calculating energy consumed in kilowatt-hours is based on the relationship between power and time, specifically using the power measured in kilowatts and the time in hours.

Energy, measured in kilowatt-hours (kWh), represents the total amount of work done or energy consumed over a period of time when a device operates at a certain power level. The formula Energy (kWh) = Power (kW) x Time (h) captures this relationship accurately. In this formula, power is expressed in kilowatts, which is a standard measurement of electrical power representing 1,000 watts. When you multiply this power by the duration in hours that the power is being consumed, you arrive at energy consumption in kilowatt-hours.

Understanding this concept is vital, for example, when assessing electricity usage on a bill or calculating the energy costs associated with operating electrical devices. The other options involve incorrect units or measures that do not appropriately relate power and time in the context of energy consumption.