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 Emissive power Emissivity None of these Absorptive power Emissive power Emissivity None of these Absorptive power ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Equivalent thickness of film Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer LMTD in case of counter flow heat exchanger as compared to parallel flow heat exchanger is Higher Same Depends on the area of heat exchanger Lower Higher Same Depends on the area of heat exchanger Lower ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Is equal to its emissivity Varies with wavelength of the incident ray Varies with temperature Does not vary with temperature and. wavelength of the incident ray Is equal to its emissivity Varies with wavelength of the incident ray Varies with temperature Does not vary with temperature and. wavelength of the incident ray ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be white when (Where a = absorptivity, p = reflectivity, x = transmissivity) P=1, T = 0 and a = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 1 P=1, T = 0 and a = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The natural convection air cooled condensers are used in Domestic refrigerators Room air conditioners All of these Water coolers Domestic refrigerators Room air conditioners All of these Water coolers ANSWER DOWNLOAD EXAMIANS APP
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