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 3 81 270 9 3 81 270 9 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The radiation emitted by a black body is known as Total radiation All of these Full radiation Black radiation Total radiation All of these Full radiation Black radiation 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 Planck's law Stefan's law Wien's law Kirchhoff's law Planck's law Stefan's law Wien's law Kirchhoff's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity is A physical property of the material A dimensionless parameter Function of temperature Used as mathematical model A physical property of the material A dimensionless parameter Function of temperature Used as mathematical model 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 Depending on the radiating properties, body will be transparent when (Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 X = 0, a + p = 1 P = 0, x= 1, and a = 0 P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 X = 0, a + p = 1 P = 0, x= 1, and a = 0 ANSWER DOWNLOAD EXAMIANS APP
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