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 Conduction Both convection and conduction Convection Radiation Conduction Both convection and conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Kirchhoff's law states that 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 The wave length corresponding to the maximum energy is proportional to the absolute temperature None of these 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 The wave length corresponding to the maximum energy is proportional to the absolute temperature None of these The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in heat transfer problems of Conduction and convection Radiation Convection Conduction Conduction and convection Radiation Convection Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fouling factor is used In case of Newtonian fluids When a liquid exchanges heat with a gas None of these In heat exchanger design as a safety factor In case of Newtonian fluids When a liquid exchanges heat with a gas None of these In heat exchanger design as a safety factor ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Is equal to its emissivity Varies with temperature Varies with wavelength of the incident ray Does not vary with temperature and. wavelength of the incident ray Is equal to its emissivity Varies with temperature Varies with wavelength of the incident ray Does not vary with temperature and. wavelength of the incident ray ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body) k. (dT/dx) (dT/dx) k. (dx/dT) k. k. (dx/dT) k. (dT/dx) (dT/dx) k. (dx/dT) k. k. (dx/dT) ANSWER DOWNLOAD EXAMIANS APP
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