Correct Answer - Option 4 : conduction
Concept:
Conduction:
- The heat transfer through direct physical contact is known as conduction.
- Heat transferred from one end to other end is called conduction.
- Heat transfer through conduction can only happen in conductors of heat like iron, copper etc.
- Heat transfer do not take place across insulators like wood, plastic etc.
Radiation:
- When electromagnetic radiation is emitted or absorbed to transfer the heat or When heat is transferred in the form of electromagnetic waves is known as radiation.
- Electromagnetic radiation includes microwaves, radio waves, infrared radiation, visible light, ultraviolet radiation, gamma rays, and X-rays.
- The method does not require any medium so heat from the sun reaches us by this method.
Convection
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It is heat transfer by the movement of its molecules.
- It occurs only in fluids (liquid and gas) not in solids because solid particles can not move from one place to another.
- For example, in a pot boiling water on the stove, or in thunderstorms, where hot air rises up to the base of the clouds.
Conclusion
The process by which heat is transferred from the hotter end to the colder end of an object is known as conduction.
In convection, the heat transfer take place through transfer of molecules while radiation takes place through electromagnetic waves.
