Concept:
- Heat Transfer: Heat is transferred from one place to another in substance due to temperature difference.
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Three modes of Transmission of heat |
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Conduction |
Convection |
Radiation |
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Heat dissipates from one place to another by molecular vibration |
Heat is transfer from one place to another by transfer of molecules |
It transfers heat in the form of electromagnetic wave |
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Conduction is relevant to solid only. |
Convection happens in liquid or gases |
It can heat any form of material. |
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Need medium to transfer heat |
Need medium to transfer heat |
No need of medium |
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Good Conductor- The objects which transfer heat easily. Ex- metals, human body etc Bad Conductor- The objects which do not transfer heat easily. Ex- Wood, Air, etc. Thermal Insulator- No heat is transferred by any means. Ex- Abonite, asbestos etc. |
When molecules are heated they headed upward and upper molecules go downward and this cyclic process continues.
Boiling of fluid |
Heat travels in terms of energy packets or waves The heat absorbed by body gain energy
Radiations of Sun |
- Evaporation: In this process, the liquid form a substance tends to convert in the gaseous phase on the uppermost surface due to heat and pressure.
- Condensation: In this process, the gaseous phase of an object tends to convert into liquid form due to pressure and temperature.
Explanation:
The other end of a wooden spoon will not become cold when it is dipped in a cup of ice cream because wood is a bad conductor, not a good conductor.


