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 Emissivity Emissive power None of these Absorptive power Emissivity Emissive power None of these Absorptive power ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by Conduction and convection Convection Radiation Conduction Conduction and convection Convection Radiation Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 63.2% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 63.2% of the value of initial temperature difference 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 60°C 40°C 66.7°C 20°C 60°C 40°C 66.7°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Free convection flow depends on Density Gravitational force All of these Coefficient of viscosity Density Gravitational force All of these Coefficient of viscosity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as the ratio of Temperature drop through the films of fluids to the thickness of film of fluids Thickness of film of fluid to the thermal conductivity Thermal conductivity to the equivalent thickness of the film of fluid Thickness of film of fluid to the temperature drop through the films of fluids Temperature drop through the films of fluids to the thickness of film of fluids Thickness of film of fluid to the thermal conductivity Thermal conductivity to the equivalent thickness of the film of fluid Thickness of film of fluid to the temperature drop through the films of fluids ANSWER DOWNLOAD EXAMIANS APP