WAEC Physics 2016 Paper

Concept:Electricity meters measure electrical energy consumed in commercial units of kilowatt-hour.Explanation:Electrical energy is calculated as power multiplied by time.When power is expressed in kilowatts ($\mathrm{kW}$) and time in hours ($\mathrm{h}$), the energy unit becomes kilowatt-hour ($\mathrm{kWh}$).This is the standard unit used by electricity meters for billing.Volt ($\mathrm{V}$) measures potential difference.Ampere ($\mathrm{A}$) measures electric current.Coulomb ($\mathrm{C}$) measures electric charge.None of these measure energy consumption.Answer:A. kilowatt-hour