For flow over a flat plate, the hydrodynamic boundary layer thickness is 0.5 mm. The dynamic viscosity is 25 x 10-6m2/s, sp. heat is 2 kJ/kg K and thermal conductivity is 0.65 W/mK. The thermal...

For flow over a flat plate, the hydrodynamic boundary layer thickness is 0.5 mm. The dynamic viscosity is 25 x 10-6m2/s, sp. heat is 2 kJ/kg K and thermal conductivity is 0.65 W/mK. The thermal boundary layer thickness would be-

(a) 0.1 m                              (b) 0.5 mm

(c) 1 mm                              (d) 2 mm