Heat and Mass Transfer The value of Prandtl number for air is about 0.7 0.1 1.7 0.3 0.7 0.1 1.7 0.3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Conduction Conduction and convection Convection Radiation Conduction Conduction and convection Convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A non-dimensional number generally associated with natural convection heat transfer is Grashoff number Nusselt number Prandtl number Weber number Grashoff number Nusselt number Prandtl number Weber number 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 = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The natural convection air cooled condensers are used in All of these Domestic refrigerators Water coolers Room air conditioners All of these Domestic refrigerators Water coolers Room air conditioners ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Varies with wavelength of the incident ray Does not vary with temperature and. wavelength of the incident ray Varies with temperature Is equal to its emissivity Varies with wavelength of the incident ray Does not vary with temperature and. wavelength of the incident ray Varies with temperature Is equal to its emissivity ANSWER DOWNLOAD EXAMIANS APP