Heat and Mass Transfer In heat transfer, conductance equals conductivity (kcal/hr/sq.m/°C/cm) divided by Sq. m (area) °C (temperature) Hr (time) K.cal (heat) Sq. m (area) °C (temperature) Hr (time) K.cal (heat) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it Reflects all heat Is black in colour Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it Reflects all heat Is black in colour ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan's law, the total radiation from a black body per second per unit area is proportional to Absolute temperature T T5 T2 Absolute temperature T T5 T2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Film coefficient × Inside diameter Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wavelength for maximum emissive power is given by Fourier's law Planck's law Stefan's law Wien’s law Fourier's law Planck's law Stefan's law Wien’s law ANSWER DOWNLOAD EXAMIANS APP
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