Heat and Mass Transfer If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of 81 270 9 3 81 270 9 3 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 66.7°C 60°C 40°C 20°C 66.7°C 60°C 40°C 20°C 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 Wien's law Kirchhoff's law Planck's law Stefan's law Wien's law Kirchhoff's law Planck's law Stefan's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Equal to Nusselt number Greater than one Less than one Equal to one Equal to Nusselt number Greater than one Less than one Equal to one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called Absorptive power None of these Emissive power Emissivity Absorptive power None of these Emissive power Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of Stefan Boltzmann constant is watt/cm2 °K⁴ watt2/cm °K⁴ watt/cm4 °K watt/cm3 °K watt/cm2 °K⁴ watt2/cm °K⁴ watt/cm4 °K watt/cm3 °K ANSWER DOWNLOAD EXAMIANS APP
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