Question

Which of the following statement regarding convection is WRONG? Select one: a. Contribution due to random molecular motion reduces as the flow progresses in perpendicular direction from the surface b. Contribution due to advection reduces as the flow progresses in perpendicular direction from the surface c. Heat transfer is dominated by random molecular motion near the surface where fluid velocity is low d. Heat transfer occurs solely due to random molecular motion at the interface between fluid and surface where the fluid velocity is zero

Answer 1

Answer: Option (d) is the correct answer.

Explanation:

Convection is defined as the process in which when heat is supplied to a fluid (liquid or gas) then denser substance (cooler) will sink at the bottom whereas less dense substance (hotter) will rise towards the top.

This intermixing of fluids leads to the generation of convection currents. This macroscopic motion of fluid particles is responsible for convection.

Also, contribution due to the random molecular motion reduces as the flow progresses in perpendicular direction from the surface. Heat transfer is dominated by random molecular motion near the surface where fluid velocity is low.

Thus, we can conclude that out of the given options wrong statement is heat transfer occurs solely due to random molecular motion at the interface between fluid and surface where the fluid velocity is zero.