Heat and Mass Transfer Thermal conductivity of air with rise in temperature Decreases Increases Remain constant May increase or decrease depending on temperature Decreases Increases Remain constant May increase or decrease depending on temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The use of heat exchangers is made in All of these Radiators in automobile Condensers and evaporators in refrigeration and air conditioning units Condensers and boilers in steam plants All of these Radiators in automobile Condensers and evaporators in refrigeration and air conditioning units Condensers and boilers in steam plants ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, body will be transparent when(Where a = absorptivity, p = reflectivity, x = transmissivity) X = 0, a + p = 1 P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 P = 0, x= 1, and a = 0 X = 0, a + p = 1 P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 P = 0, x= 1, and a = 0 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 = μ cp/k RN = ρ V l /μ RN = V²/t.cp RN = hl/k RN = μ cp/k RN = ρ V l /μ RN = V²/t.cp 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 = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Log mean temperature difference in case of counter flow compared to parallel flow will be More Depends on other factors Same Less More Depends on other factors Same Less ANSWER DOWNLOAD EXAMIANS APP
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