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 = [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)] ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the body to another by the actual motion of the heated particles, is called Convection Radiation Conduction None of these Convection Radiation Conduction None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A non-dimensional number generally associated with natural convection heat transfer is Weber number Nusselt number Prandtl number Grashoff number Weber number Nusselt number Prandtl number Grashoff number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the Reynold's number Reynold's number, Grashoff's number Grashoff's number Prandtl number, Grashoff's number Reynold's number Reynold's number, Grashoff's number Grashoff's number Prandtl number, Grashoff's number 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 9 3 270 81 9 3 270 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 0.45 0.75 0.4 0.55 0.45 0.75 0.4 0.55 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS