State whether the following statement is true or false:
Kilowatt hour $(kWh)$ is the unit of power.

$(a)$ What is the commercial unit of energy? Give its relationship with the $SI$ unit of energy.
$(b)$ An electric bulb of $60 \,W$ is used for $10$ hours every day. How many units of electrical energy are consumed by this bulb in one day?

The power of a motor pump is $2 \, kW$. How much water per minute can the pump raise to a height of $10 \, m$ (in $kg$)? (Given $g = 10 \, m \, s^{-2}$)

Which one of the following is not the unit of energy?

Calculate the power of an electric motor that can lift $800 \, kg$ of water to store in a tank at a height of $1500 \, cm$ in $20 \, s$. $(g = 10 \, m s^{-2})$ (in $, kW$)

An electric motor of power $100\, W$ is used to drive the stirrer in a water bath. If $50\%$ of the energy supplied to the motor is spent in stirring the water, calculate the work done on the water in one minute. (in $J$)