Heat and Mass Transfer Heat transfer by radiation mainly depends upon All of these Nature of the body Its temperature Kind and extent of its surface All of these Nature of the body Its temperature Kind and extent of its surface ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be 40 mm 160 mm 800 mm 25 mm 40 mm 160 mm 800 mm 25 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Absorbs heat radiations of all wave lengths falling on it Reflects all heat Is black in colour Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it Reflects all heat Is black in colour Transmits all heat radiations ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According of Kirchhoff's law Emissive power and absorptivity are constant for all bodies Emissive power depends on temperature 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 and absorptivity are constant for all bodies Emissive power depends on temperature 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 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. (dx/dT) k. A. (dT/dx) k. A. (dx/dT) k. (dT/dx) k. (dx/dT) k. A. (dT/dx) k. A. (dx/dT) k. (dT/dx) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.45 0.4 0.55 0.75 0.45 0.4 0.55 0.75 ANSWER DOWNLOAD EXAMIANS APP
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