Heat and Mass Transfer A composite slab has two layers of different materials with thermal conductivities k₁ and k₂. If each layer has the same thickness, then the equivalent thermal conductivity of the slab will be 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ k₁ k₂ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In a heat exchanger with one fluid evaporating or condensing, the surface area required is least in Cross flow Counter flow Parallel flow All of these Cross flow Counter flow Parallel flow All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two plates spaced 150 mm apart are maintained at 1000°C and 70°C. The heat transfer will take place mainly by Free convection Convection Forced convection Radiation Free convection Convection Forced convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is None of these h₁ + h₂ + h₃ (h₁.h₂.h₃)1/3 1/h₁ + 1/h₂ + 1/h₃ None of these h₁ + h₂ + h₃ (h₁.h₂.h₃)1/3 1/h₁ + 1/h₂ + 1/h₃ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Is equal to its emissivity Varies with wavelength of the incident ray Varies with temperature Does not vary with temperature and. wavelength of the incident ray Is equal to its emissivity Varies with wavelength of the incident ray Varies with temperature Does not vary with temperature and. wavelength of the incident ray ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of Stefan Boltzmann constant is watt/cm4 °K watt/cm3 °K watt2/cm °K⁴ watt/cm2 °K⁴ watt/cm4 °K watt/cm3 °K watt2/cm °K⁴ watt/cm2 °K⁴ ANSWER DOWNLOAD EXAMIANS APP
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