Heat and Mass Transfer In a heat exchanger with one fluid evaporating or condensing, the surface area required is least in Cross flow All of these Counter flow Parallel flow Cross flow All of these Counter flow Parallel flow ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is Inversely proportional to density of substance Directly proportional to the thermal conductivity All of these Inversely proportional to specific heat Inversely proportional to density of substance Directly proportional to the thermal conductivity All of these Inversely proportional to specific heat 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 = V²/t.cp RN = ρ V l /μ RN = hl/k RN = μ cp/k RN = V²/t.cp RN = ρ V l /μ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity is a Function of temperature Physical property of a substance All of these Dimensionless parameter Function of temperature Physical property of a substance All of these Dimensionless parameter 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 = 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) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of 81 270 3 9 81 270 3 9 ANSWER DOWNLOAD EXAMIANS APP
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