Page 1 - Lesson notes-Transfer of heat and Conduction

SAI International School
Class 7
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 low temperature than transfer of heat
is occurred.

There are three different ways of transfer of heat:

Ø Conduction
Ø Convection
Ø Radiation

Conduction:

Conduction is a process of transfer of heat in which the heat is transfer 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 end to another 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.