Heat Transfer Graetz number is given by kμ/mCp mCp/kL kL/mCp mCp/kμ kμ/mCp mCp/kL kL/mCp mCp/kμ ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Dropwise condensation of steam on cooling surface is promoted None of these When both the steam and the tube are clean An oily surface Only in presence of air None of these When both the steam and the tube are clean An oily surface Only in presence of air ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Grashoff number, which is defined as g . β(Ts - T∞) ρ². L³/μ², is proportional to the ratio of buoyancy force to __________ force. Viscous None of these Inertial Elastic Viscous None of these Inertial Elastic ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m².°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be Less than that of the uninsulated steam pipe Equal to that of the uninsulated steam pipe Less than the steam pipe with 5 cms insulation Greater than that for uninsulated steam pipe Less than that of the uninsulated steam pipe Equal to that of the uninsulated steam pipe Less than the steam pipe with 5 cms insulation Greater than that for uninsulated steam pipe ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Which of the following is the most widely used heat insulating material for pipelines carrying steam? Fireclay refractory followed by aluminium sheet Cotton followed by aluminium foil 85% magnesia cement and glass wool Tar dolomite bricks followed by asbestos Fireclay refractory followed by aluminium sheet Cotton followed by aluminium foil 85% magnesia cement and glass wool Tar dolomite bricks followed by asbestos ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer With increase in porosity, the thermal conductivity of a solid substance Remains unchanged Increases Decreases May increase or decrease; depends on the solid Remains unchanged Increases Decreases May increase or decrease; depends on the solid ANSWER DOWNLOAD EXAMIANS APP
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