Heat and Mass Transfer Thermal diffusivity is A physical property of the material Function of temperature A dimensionless parameter Used as mathematical model A physical property of the material Function of temperature A dimensionless parameter Used as mathematical model ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Whether to put inferior OIL over pipe or the better one would depend on steam temperature Both may be put in any order Inferior insulation should be put over pipe and better one over it Better insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Both may be put in any order Inferior insulation should be put over pipe and better one over it Better insulation should be put over pipe and better one over it 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 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 None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.55 0.75 0.45 0.4 0.55 0.75 0.45 0.4 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Film coefficient × Inside diameter Thermal conductivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Equivalent thickness of film Film coefficient × Inside diameter Thermal conductivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Equivalent thickness of film ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as Kirchhoff's law Planck's law Stefan's law Wien's law Kirchhoff's law Planck's law Stefan's law Wien's law ANSWER DOWNLOAD EXAMIANS APP
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