Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In convection, stirring of the fluid and cleaning the heating surface. In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In convection, stirring of the fluid and cleaning the heating surface. In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Kirchhoff's law states that The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature 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 None of these The wave length corresponding to the maximum energy is proportional to the absolute temperature The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature 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 None of these The wave length corresponding to the maximum energy is proportional to the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of wood depends on Temperature All of these Density Moisture Temperature All of these Density Moisture ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the Grashoff's number Prandtl number, Grashoff's number Reynold's number, Grashoff's number Reynold's number Grashoff's number Prandtl number, Grashoff's number Reynold's number, Grashoff's number Reynold's number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called Absorptive power Emissivity Emissive power None of these Absorptive power Emissivity Emissive power None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wave length for maximum emissive power is given by Wine’s law Kirchhoff’s law Stefan’s law Planck’s law Wine’s law Kirchhoff’s law Stefan’s law Planck’s law ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS