Heat and Mass Transfer When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by Convection Radiation Conduction Conduction and convection Convection Radiation Conduction Conduction and convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Equal to one Equal to Nusselt number Greater than one Less than one Equal to one Equal to Nusselt number Greater than one Less than one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Is equal to its emissivity Varies with temperature Varies with wavelength of the incident ray Does not vary with temperature and. wavelength of the incident ray Is equal to its emissivity Varies with temperature Varies with wavelength of the incident ray Does not vary with temperature and. wavelength of the incident ray ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity) RN = hl/k RN = μ cp/k RN = V²/t.cp RN = ρ V l /μ RN = hl/k RN = μ cp/k RN = V²/t.cp RN = ρ V l /μ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of solid metals with rise in temperature normally Decreases Remain constant Increases May increase or decrease depending on temperature Decreases Remain constant Increases May increase or decrease depending on temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick sphere is given by Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP
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