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 = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 1 P=1, T = 0 and a = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 1 P=1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The highest thermal diffusivity is of Concrete Lead Iron Wood Concrete Lead Iron Wood ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction gives the heat flow for Nonuniform temperature surfaces Irregular surfaces One dimensional cases only Two dimensional cases only Nonuniform temperature surfaces Irregular surfaces One dimensional cases only Two dimensional cases only ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wavelength for maximum emissive power is given by Wien’s law Fourier's law Planck's law Stefan's law Wien’s law Fourier's law Planck's law Stefan's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of overall coefficient of heat transfer is kcal/hr °C kcal/m² hr °C kcal/m² kcal/m hr °C kcal/hr °C kcal/m² hr °C kcal/m² kcal/m hr °C ANSWER DOWNLOAD EXAMIANS APP