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 25 mm 40 mm 800 mm 160 mm 25 mm 40 mm 800 mm 160 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer, One could place either insulation on either side The better insulation must be put outside One should take into account the steam temperature before deciding as to which insulation is put where The better insulation must be put inside One could place either insulation on either side The better insulation must be put outside One should take into account the steam temperature before deciding as to which insulation is put where The better insulation must be put inside ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer All radiations in a black body are Transmitted Refracted Reflected Absorbed Transmitted Refracted Reflected Absorbed ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Kirchoff's law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a Black body Brilliant white polished body Grey body Red hot body Black body Brilliant white polished body Grey body Red hot body 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. k. (dx/dT) k. k. (dT/dx) (dx/dT) (dT/dx) k. k. (dx/dT) k. k. (dT/dx) (dx/dT) (dT/dx) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat conducted through per unit area and unit thick face per unit time when temperature difference between opposite faces is unity, is called Thermal resistance Thermal conductivity Temperature gradient Thermal coefficient Thermal resistance Thermal conductivity Temperature gradient Thermal coefficient ANSWER DOWNLOAD EXAMIANS APP