Heat and Mass Transfer Unit of thermal conductivity in S.I. units is J/m² sec J/m °K sec W/m °K Option (B) and (C) above J/m² sec J/m °K sec W/m °K Option (B) and (C) above 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 0.55 0.4 0.45 0.75 0.55 0.4 0.45 0.75 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer takes place as per Kirchoff's law Zeroth law of thermodynamics Second law of the thermodynamics First law of thermodynamic Kirchoff's law Zeroth law of thermodynamics Second law of the thermodynamics First law of thermodynamic ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Emissivity of a white polished body in comparison to a black body is Depends upon the shape of body Same Lower Higher Depends upon the shape of body Same Lower Higher ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In heat exchangers, degree of approach is defined as the difference between temperatures of Hot medium outlet and cold water outlet Hot medium outlet and cold water inlet Hot medium inlet and outlet Cold water inlet and outlet Hot medium outlet and cold water outlet Hot medium outlet and cold water inlet Hot medium inlet and outlet Cold water inlet and outlet ANSWER DOWNLOAD EXAMIANS APP
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