The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is
A
Equal to one
B
Greater than one
C
Less than one
D
Equal to Nusselt number
Correct Answer: Equal to one
If the Prandtl number (Pr) is 1, the two boundary layers (hydrodynamic and thermal) are the same thickness.If the Pr > 1, the thermal boundary layer is thinner than the velocity boundary layer.