Question

State two practical units of electrical energy and define each.

Answer 1

1. Basic unit of electrical energy is joule or watt-second.
2. Electrical energy is said to be $1Joule$when $1ampere$ current flows through the circuit for a unit second when a potential difference $1Volt$ is applied across the terminal.
3. Another commercial unit of electrical energy is the kilowatt-hour (kWh).
4. $1kwh$ energy is defined as the energy consumed by a $1kilowatt$appliance in one hour.
5. It is also known as the Board of Trade unit (B.O.T).
   $$\begin{gathered} 1kwh=1000\times 60\times 60watt-second \\ 1kwh=36\times {10}^{5}W-sorjoules \end{gathered}$$