Heat and Mass Transfer A perfect black body is one which 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 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 40 mm 160 mm 25 mm 800 mm 40 mm 160 mm 25 mm 800 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? I.C. engine None of these Heating of building in winter Air preheaters I.C. engine None of these Heating of building in winter Air preheaters ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Four Two One Three Four Two One Three ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical thickness of insulation for a sphere is h₀/2k 2k/h₀ k/h₀ h₀/k h₀/2k 2k/h₀ k/h₀ h₀/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P= 1, T = 0 and a = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P= 1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
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