RadiationUsing a toaster and grilling food are good examples of using radiation to transfer heat. When heat is radiated it travels in straight lines and any object in its path becomes heated.
ConductionHeating a pan on a hob is a good illustration of conduction. In this method, heat travels through a solid, e.g. the pan. Metal objects are good conductors of heat and so these are used in the making of saucepans. Cotton is a less effective heat conductor and hence it is used in the production of oven-gloves.
ConvectionA gas oven or cooking in boiling water are good illustrations of heat being transferred by convection. When heated, the particles of a liquid (e.g. water) or a gas (e.g. air) become lighter and rise, while colder particles sink to the bottom and are then heated in turn.
© Media Matters, 1999