Revise GCSE Physics


Question:How is cooking using microwaves different to cooking using infrared radiation?

The main difference is that microwaves penetrate about 1 cm beneath the surface of the food and deliver their energy further into the food, which means that food starts cooking on the inside before heat has had time to be transferred down from the surface by conduction.

Some foods are less than a cm thick so all parts of the food are being cooked as soon as the microwaves are turned on.

Infrared radiation is completely absorbed at the surface of the food, and it takes longer for the heat to reach the inside of the food that is being cooked because foods tend to be poor conductors of heat.