Heat and Mass Transfer Stefan Boltzmann law is applicable for heat transfer by Radiation Conduction and radiation combined Conduction Convection Radiation Conduction and radiation combined Conduction Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The product of Reynolds number and Prandtl number is known as Stanton number Grashoff number Peclet number Biot number Stanton number Grashoff number Peclet number Biot number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In regenerator type heat exchanger, heat transfer takes place by A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Generation of heat again and again Direct mixing of hot and cold fluids A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Generation of heat again and again Direct mixing of hot and cold fluids 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 (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) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally Less than those for liquids Less than those for gases More than those for liquids and gases More or less same as for liquids and gases Less than those for liquids Less than those for gases More than those for liquids and gases More or less same as for liquids and gases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a Black body White body Opaque body Grey body Black body White body Opaque body Grey body ANSWER DOWNLOAD EXAMIANS APP
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