Write the relation between the commercial unit of electricity and the $SI$ unit of energy.

(N/A) The commercial unit of electrical energy is kilowatt-hour $(kWh)$.
The $SI$ unit of energy is Joule $(J)$.
Since $1 \text{ kW} = 1000 \text{ W}$ and $1 \text{ hour} = 3600 \text{ seconds}$,
$1 \text{ kWh} = 1000 \text{ J/s} \times 3600 \text{ s} = 3.6 \times 10^{6} \text{ J}$.
Therefore,the relation is $1 \text{ kWh} = 3.6 \times 10^{6} \text{ J}$.