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SAI International School

Class VII
Lesson Notes

Subject: Physics
Ch-Heat and temperature
Subtopic: Transfer of heat and Conduction

Methods of heat transfer:

When heat flows from a body at high temperature to a body at low temperature then
transfer of heat is occurred.

There are three different ways of transfer of heat:

 Conduction
 Convection
 Radiation

Conduction:

Conduction is a process of transfer of heat in which the heat is transferred from hot object
to cold object without actual movement of particles.

 Heat transfer in solids takes place through conduction.
 When we heat solid metals, their particles vibrate vigorously. These vibrating particles
collide and transfer energy from one end to another end of objects.

Condition necessary for conduction of heat:

The condition necessary for heat to be conducted are as follows:

I. The two bodies should be in contact or touch each other.
II. The temperature of both the bodies should be different (for heat to flow).

Conductors and Insulators:

All materials do not conduct heat in same way. Depending upon the ability of conduction,
substances are classified as Conductors and Insulators.

Conductors: Materials that allow the heat energy to pass through them easily are called
Conductors.

 Most metals are good conductors of heat
 Metals have free electrons to carry heat from one end to another.
 Silver is the best conductor of heat.