Heat and Mass Transfer Unit of thermal conductivity in M.K.S. units is K cal m/hr m² °C K calm/hr °C K cal/hr m² °C K cal/kg m² °C K cal m/hr m² °C K calm/hr °C K cal/hr m² °C K cal/kg m² °C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According of Kirchhoff's law Emissive power depends on temperature Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Emissive power depends on temperature Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally More or less same as for liquids and gases More than those for liquids and gases Less than those for gases Less than those for liquids More or less same as for liquids and gases More than those for liquids and gases Less than those for gases Less than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity) RN = ρ V l /μ RN = μ cp/k RN = V²/t.cp RN = hl/k RN = ρ V l /μ RN = μ cp/k RN = V²/t.cp RN = hl/k 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 25 mm 160 mm 40 mm 800 mm 25 mm 160 mm 40 mm 800 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Wien's law, the wavelength corresponding to maximum energy is proportion to Absolute temperature (T) T I² F Absolute temperature (T) T I² F ANSWER DOWNLOAD EXAMIANS APP
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