Question

Which of the following situations explains the meaning of free convection?

• A. Air conditioning installations in nuclear reactors
• B. Flow of water inside the condenser tubes
• C. Cooling of internal combustion engine
• D. Drying of clothes in the sun

Answer 1

The correct option is D Drying of clothes in the sun

Free convection is also known as natural convection.
Free convection is a mechanism, or type of mass and heat transport in which the fluid motion is generated by difference in density in the fluid occurring due to difference in temperature, not by any external source (like a pump, fan, suction device, etc).
Drying of clothes in the sun is a natural process and doesn't require an external force where as, all the other options being an example of convection does not occur naturally.