What is the meaning of the symbol kWh? Which quantity does it represent?

Name the quantity whose unit is (i) kilowatt, and (ii) kilowatt-hour.

Which quantity has the unit of watt?

If the potential difference between the end of a wire of fixed resistance is doubled, by how much does the electric power increase?

An electric lamp is labeled 12 V, 36 W. This indicates that it should be used with a 12 V supply. What other information does the label provide?