Hot air flows through a pipe, as shown above. the properties of air may be taken as: k=0.03 w/m-k, pr=0.7, μ=208.2 x 10"n s/m^2 and ρ=0995 kg/m^3. calculate heat transfer coefficient between the inner surface of the pipe and the hot air.

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk