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. None of these Equal to Directly proportional to Inversely proportional to None of these Equal to Directly proportional to Inversely proportional to ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Three One Two Four Three One Two Four ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wave length for maximum emissive power is given by Kirchhoff’s law Stefan’s law Wine’s law Planck’s law Kirchhoff’s law Stefan’s law Wine’s law Planck’s law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The natural convection air cooled condensers are used in Domestic refrigerators Water coolers All of these Room air conditioners Domestic refrigerators Water coolers All of these Room air conditioners ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of heat flow through a body is Q = [kA (T₁ - T₂)]/x. The term x/kA is known as Thermal resistance None of these Thermal coefficient Thermal conductivity Thermal resistance None of these Thermal coefficient Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Planck’s law holds good for black bodies All of these all coloured bodies polished bodies black bodies All of these all coloured bodies polished bodies ANSWER DOWNLOAD EXAMIANS APP
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