Heat Transfer The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by Painting the surface black Roughening the surface Painting the surface white (with aluminium paint) Giving the surface a mirror finish Painting the surface black Roughening the surface Painting the surface white (with aluminium paint) Giving the surface a mirror finish ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are Nu, Pr Nu, Gz Nu, Pr, Re Re.Gz Nu, Pr Nu, Gz Nu, Pr, Re Re.Gz ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Hot water (0.01 m³ /min) enters the tube side of a counter current shell and tube heat exchanger at 80°C and leaves at 50°C. Cold oil (0.05 m³/min) of density 800 kg/m³ and specific heat of 2 kJ/kg.K enters at 20°C. The log mean temperature difference in °C is approximately 50 37 32 45 50 37 32 45 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Nucleate boiling is promoted In the absence of agitation On polished surfaces On rough surfaces None of these In the absence of agitation On polished surfaces On rough surfaces None of these ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Which of the following has maximum thermal conductivity? Coal Nitrogen Iron Tar Coal Nitrogen Iron Tar ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer With increase in temperature, the thermal conductivity of steel Remains unchanged Increases exponentially Decreases Increases Remains unchanged Increases exponentially Decreases Increases ANSWER DOWNLOAD EXAMIANS APP
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