Process of moving heat from one source to another source is called heat

Process of moving heat from one source to another source is called heat transfer.

The movement of heat energy from one place to another place Heat transfer may be accomplished in three ways:-

(a) Conduction (b) Convection (c) Radiation.

(A) Conduction:

Transfer of heat through solid material. Heat is carried through the atomic vibration & electron motion

It is due to the property of matter.

Process of heat transfer from one molecule of the body to another molecule without the motion of molecule.

(b) Convection:

Heat transferred via a fluid i.e. gas, air, liquid water. Process of heat transfer from one particle of the fluid to another particle by the accumulation of the heated particles of the fluid. Heat is carried by molecules

It is due to the capacity of moving matter to carry heat energy. Heat transfer is by heat conduction & mixing motion.

Heat from the hot surface is given to the particles of the liquid, gas adjacent to the surface by conduction.

(C) Radiation:

Process of heat transfer from one hot body to another cold body in a straight line without affecting intervening medium. Radiation is the property fold substances & each body emits energy & amount of energy emitted depends upon the temperature level Radiation energy falling on the body is partly reflected& party transmitted & partly absorbed.

Solid – Strong absorber.

Absorption occurs in a very thin region of surface.

Black body 100% absorption.

White body – reflection 100%

Transparent body- 100% transmitted.

Opaque bodies – do not transmit any radiation energy.