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 The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Intensity of radiation Transmissivity Reflectivity Emissivity Intensity of radiation Transmissivity Reflectivity Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The product of Reynolds number and Prandtl number is known as Peclet number Stanton number Grashoff number Biot number Peclet number Stanton number Grashoff number Biot number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When α is absorptivity, ρ is reflectivity and τ is transmissivity, then for a diathermanous body, α = 0, ρ = 1 and τ = 0 α = 1, ρ = 0 and τ = 0 α = 0, ρ = 0 and τ = 1 α + ρ = 1 and τ = 0 α = 0, ρ = 1 and τ = 0 α = 1, ρ = 0 and τ = 0 α = 0, ρ = 0 and τ = 1 α + ρ = 1 and τ = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain the final temperature to be measured The time taken to attain 63.2% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 63.2% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Varies with temperature Does not vary with temperature and. wavelength of the incident ray Varies with wavelength of the incident ray Is equal to its emissivity Varies with temperature Does not vary with temperature and. wavelength of the incident ray Varies with wavelength of the incident ray Is equal to its emissivity ANSWER DOWNLOAD EXAMIANS APP
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