Introduction:-
Heat transfer means the flow of heat from a region of higher temperature to another region of lower temperature through a medium or in the absence of any medium. As such, heat is a form of energy.
Heat transfer occurs mainly through 3 ways as follows -
1) Conduction
2) Convection
3) Radiation
1) Conduction:- It is the mode of heat transfer which occurs between 2 regions in direct contact with temperature gradient by means of lattice vibration or free-electron transfer.
Example: Heat flow from our body to the thermometer.
2) Convection:- It is the mode of heat transfer which occurs between 2 regions of a body with temperature gradients by the actual motion of matters within the body.
Example: Boiling of water
3) Radiation:- It is the mode of heat transfer that takes place between two bodies with temperature gradient and separated by vacuum in the form of electromagnetic waves.
Example: Heating of a body by solar energy.