Question

The commercial unit of electric energy is commonly known as ‘unit’. Write its actual name and establish the relationship between this unit and the SI unit of energy.

Hint:

Commercial meters measure energy in kWh, SI units in Joules.

Answer 1

The commercial measurement of electrical energy is the kilowatt-hour (kWh). - One electricity unit equals one kilowatt-hour. Relation to the SI unit: The SI unit for energy is the Joule (J). \[ 1 \text{ kWh} = 1 \text{ kilowatt} \times 1 \text{ hour} = 1000 \text{ W} \times 3600 \text{ s} = 3,600,000 \text{ J} = 3.6 \times 10^6 \text{ J} \] Hence, \[ 1 \text{ unit} = 1 \text{ kWh} = 3.6 \times 10^6 \text{ Joules}. \]