Heat and Mass Transfer In regenerator type heat exchanger, heat transfer takes place by Generation of heat again and again A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Direct mixing of hot and cold fluids Generation of heat again and again A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Direct mixing of hot and cold fluids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat of sun reaches to us according to None of these Convection Conduction Radiation None of these Convection Conduction Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of heat flow through a body is Q = [kA (T₁ - T₂)]/x. The term x/kA is known as None of these Thermal conductivity Thermal resistance Thermal coefficient None of these Thermal conductivity Thermal resistance Thermal coefficient ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity is A dimensionless parameter Used as mathematical model Function of temperature A physical property of the material A dimensionless parameter Used as mathematical model Function of temperature A physical property of the material ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Upto the critical radius of insulation, Convective heat loss will be less than conductive heat loss Heat flux will decrease Added insulation will decrease heat loss Added insulation will increase heat loss Convective heat loss will be less than conductive heat loss Heat flux will decrease Added insulation will decrease heat loss Added insulation will increase heat loss 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 = 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)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
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