In which of the following units, calorific value of a fuel can be expressed?

Joules per kilogram kilojoules per kilogram calories per kilogram kilocalories per kilogram

kilojoules per kilogram

The correct answer is option 2. kilojoules per kilogram. The amount of heat energy produced on the complete combustion of 1 kg of a fuel is called its calorific value. The calorific value of a fuel is expressed in a unit called kilojoule per kilogram (kJ/kg).