Question

Explain three modes of transmission of heat; i.e., conduction, convection and radiation, with the
help of their applications.

Answer 1

Here is your answer -

I) Conduction - It is the process of transfer of heat energy in solids, from one particle to another, without the actual movement of the particles.

It usually occurs in solids.
In this, only the molecules vibrates but not the actual substance.

For ex - When we keep a vessel on a hot stove, it becomes hot just due to conduction. As when heat is given the molecules of that substance transfer the heat by vibrating.

II) Convection - It is the mode of transfer of heat energy wherein the molecules actually move from one part of the substance to the other.

It occurs in liquids and gases.
In solids the molecules are very tightly packed so, they can only vibrate but in liquids and gases there are loosely packed molecules so, it can occur in liquids and gases.

For ex - When water is heated from below the beaker then on getting heated, water expands and becomes less dense and this dense hot water rises up. This show the convention current in water.

IIi) When the heat energy is transferred from a hot body to cold body directly without heating the space between, and do not require any medium for it, is called Radiation.

It occurs in gases.
As, gases have very loosely packed molecules so heat transfer is easy.

For ex - When the sun reaches the Earth. We get the heat of the sun through Radiation as there is heat energy transferred with no medium involved.

Answer 2

Answer:

In conduction, heat transfer occurs between objects by direct contact. In convection, the heat transfer takes within the fluid. In radiation, heat transfer occurs through electromagnetic waves without involving particles. The heat transfer takes place due to the difference in temperature.