Heat and Mass Transfer According to Stefan Boltzmann law, the total radiation from a black body per second per unit area is directly proportional to the Square of the absolute temperature Cube of the absolute temperature Fourth power of the absolute temperature Absolute temperature Square of the absolute temperature Cube of the absolute temperature Fourth power of the absolute temperature Absolute temperature 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 One Three Four Two One Three Four Two ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The expression Q = ρ AT4 is called Stefan-Boltzmann equation Joseph-Stefan equation Newton Reichmann equation Fourier equation Stefan-Boltzmann equation Joseph-Stefan equation Newton Reichmann equation Fourier equation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body) k. (dx/dT) k. (dT/dx) k. A. (dx/dT) k. A. (dT/dx) k. (dx/dT) k. (dT/dx) k. A. (dx/dT) k. A. (dT/dx) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two balls of same material and finish have their diameters in the ratio of 2: 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of 0.16736111111111 0.084027777777778 0.043055555555556 0.042361111111111 0.16736111111111 0.084027777777778 0.043055555555556 0.042361111111111 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of glass wool varies from sample to sample because of variation in All of these Density Porosity Composition All of these Density Porosity Composition ANSWER DOWNLOAD EXAMIANS APP
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