Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat is closely related with Liquids Energy Temperature Entropy Liquids Energy Temperature Entropy ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Does not vary with temperature and. wavelength of the incident ray Varies with temperature Varies with wavelength of the incident ray Is equal to its emissivity Does not vary with temperature and. wavelength of the incident ray Varies with temperature Varies with wavelength of the incident ray Is equal to its emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The amount of radiation mainly depends upon the Temperature of the body Nature of the body Type of surface of the body All of these Temperature of the body Nature of the body Type of surface of the body All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In convection, stirring of the fluid and cleaning the heating surface. All of these In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In radiation, increasing the temperature and reducing the emissivity. In convection, stirring of the fluid and cleaning the heating surface. All of these In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In radiation, increasing the temperature and reducing the emissivity. ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Newton's law of cooling, the heat transfer from a hot body to a cold body is Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) Both (A) and (B) Directly proportional to the surface area Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) Both (A) and (B) Directly proportional to the surface area ANSWER DOWNLOAD EXAMIANS APP
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