Heat and Mass Transfer The thermal diffusivities for solids are generally More or less same as for liquids and gases Less than those for gases Less than those for liquids More than those for liquids and gases More or less same as for liquids and gases Less than those for gases Less than those for liquids More than those for liquids and gases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 20°C 66.7°C 40°C 60°C 20°C 66.7°C 40°C 60°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of air at room temperature in kcal/m hr °C is of the order of 0.01 0.1 0.02 0.002 0.01 0.1 0.02 0.002 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Planck’s law holds good for All of these all coloured bodies black bodies polished bodies All of these all coloured bodies black bodies polished bodies 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 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 h₁ + h₂ + h₃ 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 surface area Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) Directly proportional to the surface area Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) ANSWER DOWNLOAD EXAMIANS APP