Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to 1 -1 =-1/3 =-2/3 1 -1 =-1/3 =-2/3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally Less than those for gases More than those for liquids and gases Less than those for liquids More or less same as for liquids and gases Less than those for gases More than those for liquids and gases Less than those for liquids More or less same as for liquids and gases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer in liquid and gases takes place by Radiation Conduction Convection Conduction and convection Radiation Conduction Convection Conduction and convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a White body Black body Opaque body Grey body White body Black body Opaque body Grey body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer LMTD in case of counter flow heat exchanger as compared to parallel flow heat exchanger is Depends on the area of heat exchanger Higher Same Lower Depends on the area of heat exchanger Higher Same Lower ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According of Kirchhoff's law 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 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 ANSWER DOWNLOAD EXAMIANS APP