Heat and Mass Transfer Thermal conductivity of water _________ with rise in temperature. Remain same Decreases Increases May increase or decrease depending upon temperature Remain same Decreases Increases May increase or decrease depending upon temperature 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 = hl/k RN = ρ V l /μ RN = V²/t.cp RN = μ cp/k RN = hl/k RN = ρ V l /μ RN = V²/t.cp RN = μ cp/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Is black in colour Transmits all heat radiations Reflects all heat Absorbs heat radiations of all wave lengths falling on it Is black in colour Transmits all heat radiations Reflects all heat Absorbs heat radiations of all wave lengths falling on it 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 800 mm 25 mm 160 mm 40 mm 800 mm 25 mm 160 mm 40 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat is transferred by conduction, convection and radiation in Boiler furnaces None of these Melting of ice Condensation of steam in condenser Boiler furnaces None of these Melting of ice Condensation of steam in condenser ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling ANSWER DOWNLOAD EXAMIANS APP