Heat and Mass Transfer Thermal conductivity of non-metallic amorphous solids with decrease in temperature Decreases Remain constant Increases May increase or decrease depending on temperature Decreases Remain constant Increases May increase or decrease depending on temperature 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 40 mm 160 mm 25 mm 800 mm 40 mm 160 mm 25 mm 800 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water at 20°C is of the order of 0.23 0.42 0.1 0.51 0.23 0.42 0.1 0.51 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. k. k. (dx/dT) (dT/dx) (dx/dT) k. (dT/dx) k. k. k. (dx/dT) (dT/dx) (dx/dT) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is h₁ + h₂ + h₃ 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 None of these h₁ + h₂ + h₃ 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Conduction and convection Radiation Conduction Convection Conduction and convection Radiation Conduction Convection ANSWER DOWNLOAD EXAMIANS APP
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