Question

Distinguish between free convection and forced convection.

Answer 1

	Free convection	Forced convection
i.	When a hot body is in contact with air under ordinary conditions, like air around a firewood, the air removes heat from the body by a process called free or natural convection.	The convection process can be accelerated by employing a fan to create a rapid circulation of fresh air. This is called forced convection.
ii.	Land and sea breezes are formed as a result of free convection currents in air.	Heat convector, air conditioner, heat radiators in IC engine etc. operate using forced convection.