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 = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of wood depends on Density Temperature All of these Moisture Density Temperature All of these Moisture ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as the ratio of Thickness of film of fluid to the thermal conductivity Temperature drop through the films of fluids to the thickness of film of fluids Thermal conductivity to the equivalent thickness of the film of fluid Thickness of film of fluid to the temperature drop through the films of fluids Thickness of film of fluid to the thermal conductivity Temperature drop through the films of fluids to the thickness of film of fluids Thermal conductivity to the equivalent thickness of the film of fluid Thickness of film of fluid to the temperature drop through the films of fluids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According of Kirchhoff's law Emissive power and absorptivity are constant for all bodies Emissive power depends on temperature Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies Emissive power depends on temperature Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Radiant heat is proportional to fourth power of absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Intensity of radiation Transmissivity Reflectivity Emissivity Intensity of radiation Transmissivity Reflectivity Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Equal to one Equal to Nusselt number Greater than one Less than one Equal to one Equal to Nusselt number Greater than one Less than one ANSWER DOWNLOAD EXAMIANS APP
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