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 Emissivity Absorptive power Emissive power None of these Emissivity Absorptive power Emissive power None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally Less than those for liquids More or less same as for liquids and gases Less than those for gases More than those for liquids and gases Less than those for liquids More or less same as for liquids and gases Less than those for gases More than those for liquids and gases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Radiation is the process of heat transfer in which heat flows from a ________, in a straight line, without affecting the intervening medium. Larger body to smaller body Cold body to hot body Hot body to cold body Smaller body to larger body Larger body to smaller body Cold body to hot body Hot body to cold body Smaller body to larger body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Total emissivity of polished silver compared to black body is Higher Very much lower Same More or less same Higher Very much lower Same More or less same ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In convection, stirring of the fluid and cleaning the heating surface. All of these In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In convection, stirring of the fluid and cleaning the heating surface. All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Sensible heat factor is given by (where S.H. = Sensible heat, and L.H. = Latent heat) (S.H + L.H) /S.H (L.H - S.H)/S.H S.H/(S.H + L.H) S.H/(L.H - S.H) (S.H + L.H) /S.H (L.H - S.H)/S.H S.H/(S.H + L.H) S.H/(L.H - S.H) ANSWER DOWNLOAD EXAMIANS APP
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