Physics

Problem

Which statement correctly explains why domestic electricity consumption is expressed in kilowatt-hour rather than joule? a)

\text{Kilowatt-hour is the SI unit of electrical energy, while the joule is used only for mechanical energy.}

\text{Kilowatt-hour represents the rate of power consumption, whereas joule gives the total energy consumed.}

\text{Kilowatt-hour is a larger unit of energy, so the numerical readings on electricity meters and bills remain conveniently small.}

\text{Joule is a larger unit than kilowatt-hour and would make electricity bills difficult to calculate accurately.}