Heat and Mass Transfer In a heat exchanger with one fluid evaporating or condensing, the surface area required is least in Parallel flow All of these Cross flow Counter flow Parallel flow All of these Cross flow Counter flow 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. All of these 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. In radiation, increasing the temperature and reducing the emissivity. All of these 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. 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 Four Three Two One Four Three Two One 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. (dT/dx) k. (dx/dT) k. A. (dT/dx) k. A. (dx/dT) k. (dT/dx) k. (dx/dT) k. A. (dT/dx) k. A. (dx/dT) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be 160 mm 800 mm 25 mm 40 mm 160 mm 800 mm 25 mm 40 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) P = 0, x = 0 and a = 1 P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
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