Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In convection, stirring of the fluid and cleaning the heating surface. In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In convection, stirring of the fluid and cleaning the heating surface. In radiation, increasing the temperature and reducing the emissivity. ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to =-2/3 -1 =-1/3 1 =-2/3 -1 =-1/3 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In a heat exchanger with one fluid evaporating or condensing, the surface area required is least in Cross flow All of these Counter flow Parallel flow Cross flow All of these Counter flow Parallel flow ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water _________ with rise in temperature. May increase or decrease depending upon temperature Decreases Remain same Increases May increase or decrease depending upon temperature Decreases Remain same Increases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Log mean temperature difference in case of counter flow compared to parallel flow will be Same Depends on other factors Less More Same Depends on other factors Less More 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 0.084027777777778 0.16736111111111 0.042361111111111 0.043055555555556 0.084027777777778 0.16736111111111 0.042361111111111 0.043055555555556 ANSWER DOWNLOAD EXAMIANS APP
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