Heat and Mass Transfer According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to Square of temperature Fourth power of temperature Fourth power of absolute temperature Absolute temperature Square of temperature Fourth power of temperature Fourth power of absolute temperature Absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The highest thermal diffusivity is of Lead Iron Concrete Wood Lead Iron Concrete Wood 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 Emissivity Absorptive power None of these Emissive power Emissivity Absorptive power 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 conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In radiation, increasing the temperature and reducing the emissivity. In convection, stirring of the fluid and cleaning the heating surface. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In radiation, increasing the temperature and reducing the emissivity. ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law. Directly proportional to Inversely proportional to Equal to None of these Directly proportional to Inversely proportional to Equal to None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer by radiation mainly depends upon Its temperature Kind and extent of its surface Nature of the body All of these Its temperature Kind and extent of its surface Nature of the body All of these ANSWER DOWNLOAD EXAMIANS APP
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