Heat and Mass Transfer The amount of heat flow through a body by conduction is Directly proportional to the temperature difference on the two faces of the body All of these Directly proportional to the surface area of the body Dependent upon the material of the body Directly proportional to the temperature difference on the two faces of the body All of these Directly proportional to the surface area of the body Dependent upon the material of the body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water _________ with rise in temperature. Increases Remain same Decreases May increase or decrease depending upon temperature Increases Remain same Decreases May increase or decrease depending upon temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Log mean temperature difference in case of counter flow compared to parallel flow will be Same Less Depends on other factors More Same Less Depends on other factors More ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Varies with wavelength of the incident ray Is equal to its emissivity Does not vary with temperature and. wavelength of the incident ray Varies with temperature Varies with wavelength of the incident ray Is equal to its emissivity Does not vary with temperature and. wavelength of the incident ray Varies with temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred by molecular collision, it is referred to as heat transfer by Convection Conduction Radiation Scattering Convection Conduction Radiation Scattering ANSWER DOWNLOAD EXAMIANS APP