Heat and Mass Transfer Which of the following property of air does not increase with rise in temperature? Thermal conductivity Dynamic viscosity Thermal diffusivity Density Thermal conductivity Dynamic viscosity Thermal diffusivity Density ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy transferred by convection to that by conduction is called Biot number Stanton number Nusselt number Peclet number Biot number Stanton number Nusselt number Peclet number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Transmits all heat radiations Reflects all heat Absorbs heat radiations of all wave lengths falling on it Is black in colour Transmits all heat radiations Reflects all heat Absorbs heat radiations of all wave lengths falling on it Is black in colour ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The use of heat exchangers is made in Radiators in automobile Condensers and boilers in steam plants Condensers and evaporators in refrigeration and air conditioning units All of these Radiators in automobile Condensers and boilers in steam plants Condensers and evaporators in refrigeration and air conditioning units All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally More than those for liquids Dependent on the viscosity Less than those for liquids More than those for solids More than those for liquids Dependent on the viscosity Less than those for liquids More than those for solids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is (h₁.h₂.h₃)1/3 1/h₁ + 1/h₂ + 1/h₃ h₁ + h₂ + h₃ None of these (h₁.h₂.h₃)1/3 1/h₁ + 1/h₂ + 1/h₃ h₁ + h₂ + h₃ None of these ANSWER DOWNLOAD EXAMIANS APP