Question

how much joule of work done equal to one unit of energy?

Answer 1

The SI unit of energy is same as that of work i.e Joule.

The Energy unit for electricity is kWh(kilowatt-hour).
1 W = 1 J/s
1kW = 1000 J/s
​​1kWh = 1000$\times 3600$ J
1kWh = $3.6\times {10}^{6}J$
So, one unit = ​$3.6\times {10}^{6}J$