Heat Transfer Absorptivity and refletivity of a perfect black body are respectively 1 and 0 0 and 1 1 and ? 0 and 0.5 1 and 0 0 and 1 1 and ? 0 and 0.5 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m³ and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m².K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is 0.15 55.5 0.55 555 0.15 55.5 0.55 555 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of 6.1 1.74 37 1 6.1 1.74 37 1 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The ratio of momentum diffusivity to thermal diffusivity is the __________ number. Stanton Nusselt Prandtl Grashoff Stanton Nusselt Prandtl Grashoff ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The most conducive surface for dropwise condensation to occur is the __________ surface. Coated Oily Glazed & polished Smooth Coated Oily Glazed & polished Smooth ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids? At high fluid velocity None of these When fluid flows past a smooth surface At low velocity At high fluid velocity None of these When fluid flows past a smooth surface At low velocity ANSWER DOWNLOAD EXAMIANS APP
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