Heat and Mass Transfer Thermal conductivity of air with rise in temperature Remain constant May increase or decrease depending on temperature Increases Decreases Remain constant May increase or decrease depending on temperature Increases Decreases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by Convection Radiation Both convection and conduction Conduction Convection Radiation Both convection and conduction Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 20°C 66.7°C 40°C 60°C 20°C 66.7°C 40°C 60°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According of Kirchhoff's law 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 depends on temperature Emissive power and absorptivity are constant for all bodies 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 depends on temperature Emissive power and absorptivity are constant for all bodies ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as Stefan's law Kirchhoff's law Wien's law Planck's law Stefan's law Kirchhoff's law Wien's law Planck's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Moisture would find its way into insulation by vapour pressure unless it is prevented by High thickness of insulation Less thermal conductivity insulator A vapour seal High vapour pressure High thickness of insulation Less thermal conductivity insulator A vapour seal High vapour pressure ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS