Chapter 6, Problem 42R

To determine

To Choose: The correct option.

Explanation of Solution

Introduction:

Electrical poweris the rate at which electrical energy is converted to another form of energy.

Mathematically it can be written as:

P=E/t

E=Pt

Where, $E$ is the electrical energy provided by the power company in kilowatt-hours, $P$ is the power of an appliance in kilowatts, and $t$ is time in hours for which the energy is provided.

Electrical energy is usually measured in units of kilowatt-hours(kWh).

Conclusion: Option A. kilowatt-hour is a commonly used unit for electrical energy.