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For which of these configurations is a minimum temperature difference required for natural convection to set in 

For which of these configurations is a minimum temperature difference required for natural convection to set in  Correct Answer Fluid over a heated horizontal plate 

Explanation:

  • The mechanism of heat transfer or fluid motion due to density difference is known as free convection.
  • The warmer fluid is replaced by colder fluid creating convection current. The force which induces these convection is called a buoyancy force which is due to the presence of a density gradient within the fluid and a body force.
  • For free convection Nusselt number is a function of Prandlt number and Grashof Number.
  • For fluid over a heated horizontal plate, Grashof number is maximum so Nusselt number will also be maximum i.e. convection dominates. So minimum temperature difference will be required fluid over a horizontal plate. 

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