Q. 42 Consider one dimensional steady state heat conduction across a wall (as shown in figure below) of thickness 30 mm and thermal conductivity 15 W/m.K. At x = 0, a constant heat flux, q" = 1 x 105 W/m is applied. On the other side of the wall, heat is removed from the wall by convection with a fluid at 25C and heat transfer coefficient of 250 W/m.K. The temperature (in C), at x=0 is W q" 1105 W/m T T = 25C x= = 0 Q. 43 Water flows through a pipe having an inner radius of 10 mm at the rate of 36 kg/hr at 25C. The viscosity of water at 25C is 0.001 kg/m.s. The Reynolds number of the flow is Q. 44 For a fully developed flow of water in a pipe having diameter 10 cm, velocity 0.1 m/s and kinematic viscosity 10-5 m/s, the value of Darcy friction factor is