Heat and Mass Transfer If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of 9 81 270 3 9 81 270 3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Inferior insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Better insulation should be put over pipe and better one over it Both may be put in any order Inferior insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Better insulation should be put over pipe and better one over it Both may be put in any order ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water at 20°C is of the order of 0.42 0.23 0.1 0.51 0.42 0.23 0.1 0.51 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Film coefficient × Inside diameter Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the Reynold's number, Grashoff's number Prandtl number, Grashoff's number Reynold's number Grashoff's number Reynold's number, Grashoff's number Prandtl number, Grashoff's number Reynold's number Grashoff's number ANSWER DOWNLOAD EXAMIANS APP