Heat and Mass Transfer The amount of radiation mainly depends upon the All of these Temperature of the body Type of surface of the body Nature of the body All of these Temperature of the body Type of surface of the body Nature of the body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of surface convection resistance to the internal conduction resistance is known as Biot number Prandtl number Stanton number Grashoff number Biot number Prandtl number Stanton number Grashoff number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is 1/h₁ + 1/h₂ + 1/h₃ None of these h₁ + h₂ + h₃ (h₁.h₂.h₃)1/3 1/h₁ + 1/h₂ + 1/h₃ None of these h₁ + h₂ + h₃ (h₁.h₂.h₃)1/3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following property of air does not increase with rise in temperature? Thermal conductivity Density Thermal diffusivity Dynamic viscosity Thermal conductivity Density Thermal diffusivity Dynamic viscosity 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 = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) 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 0.75 0.45 0.55 0.4 0.75 0.45 ANSWER DOWNLOAD EXAMIANS APP
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