Read the information given below.

The basic principle of a microwave oven is to generate microwave radiation of appropriate frequency in the working space of the oven where we keep food. This way energy is not wasted in heating up the vessel. In the conventional heating method, the vessel on the burner gets heated first and then the food inside gets heated because of transfer of energy from the vessel. In the microwave oven, on the other hand, energy is directly delivered to water molecules which is shared by the entire food.

The basic principle of a microwave oven is

Resonant frequency of water molecule

The correct answer is option (3) : Resonant frequency of water molecule

The basic principle of microwave oven is the resonant frequency of water molecules.