Heat transfer by convection in a liquid is due to the ______?

A. Latent heat of vaporization of the liquid
B. Increased vibration of the molecules of the liquid about theit mean position
C. Variation of density of the liquid
D. Expansion of the liquid as it is heated

Correct Answer:

Option D – Expansion of the liquid as it is heated

Explanation

Liquids and gases expand when they are heated. The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it rises into the cold areas.