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 k₁ k₂ (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) 2 k₁ k₂/ (k₁ + k₂) k₁ k₂ (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) 2 k₁ k₂/ (k₁ + k₂) 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 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 None of these h₁ + h₂ + h₃ 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat conducted through per unit area and unit thick face per unit time when temperature difference between opposite faces is unity, is called Temperature gradient Thermal conductivity Thermal resistance Thermal coefficient Temperature gradient Thermal conductivity Thermal resistance Thermal coefficient ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is Inversely proportional to density of substance All of these Inversely proportional to specific heat Directly proportional to the thermal conductivity Inversely proportional to density of substance All of these Inversely proportional to specific heat Directly proportional to the thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit Thickness Time Temperature Area Thickness Time Temperature Area ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law. Directly proportional to Inversely proportional to None of these Equal to Directly proportional to Inversely proportional to None of these Equal to ANSWER DOWNLOAD EXAMIANS APP
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