Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in heat transfer problems of Convection Conduction Conduction and convection Radiation Convection Conduction Conduction and convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Total emissivity of polished silver compared to black body is Very much lower More or less same Higher Same Very much lower More or less same Higher Same ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Wien’s law states that the wave length corresponding to ________ is proportional to the absolute temperature. Minimum energy Maximum energy Both (A) and (B) None of these Minimum energy Maximum energy Both (A) and (B) None of these 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 60°C 66.7°C 40°C 20°C 60°C 66.7°C 40°C 20°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the energy absorbed by the body to total energy falling on it is called Absorptivity Absorptive power Emissivity Emissive power Absorptivity Absorptive power Emissivity Emissive power ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When α is absorptivity, ρ is reflectivity and τ is transmissivity, then for a diathermanous body, α = 1, ρ = 0 and τ = 0 α = 0, ρ = 0 and τ = 1 α = 0, ρ = 1 and τ = 0 α + ρ = 1 and τ = 0 α = 1, ρ = 0 and τ = 0 α = 0, ρ = 0 and τ = 1 α = 0, ρ = 1 and τ = 0 α + ρ = 1 and τ = 0 ANSWER DOWNLOAD EXAMIANS APP