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 0.4 0.45 0.55 0.75 0.4 0.45 0.55 0.75 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. In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In convection, stirring of the fluid and cleaning the heating surface. In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these 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 None of these Emissive power Absorptive power Emissivity None of these Emissive power Absorptive power Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the Reynold's number Grashoff's number Prandtl number, Grashoff's number Reynold's number, Grashoff's number Reynold's number Grashoff's number Prandtl number, Grashoff's number Reynold's number, Grashoff's number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Unit of thermal conductivity in M.K.S. units is K calm/hr °C K cal m/hr m² °C K cal/kg m² °C K cal/hr m² °C K calm/hr °C K cal m/hr m² °C K cal/kg m² °C K cal/hr m² °C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is smallest in None of these Solids Liquids Gases None of these Solids Liquids Gases ANSWER DOWNLOAD EXAMIANS APP
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