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 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 Painting the surface black Roughening the surface ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The value of Stefan-Boltazman constant in SI unit is 0.1714 x 10-8kcal/m². °K4 5.6697 x 10-8W/m².°K4 0.1714 x 10-8W/m².°K4 5.6697 x 10-8kcal/m² . °K4 0.1714 x 10-8kcal/m². °K4 5.6697 x 10-8W/m².°K4 0.1714 x 10-8W/m².°K4 5.6697 x 10-8kcal/m² . °K4 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer With increase in temperature, the thermal conductivity of steel Increases Decreases Remains unchanged Increases exponentially Increases Decreases Remains unchanged Increases exponentially ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Which of the following parameters is increased by use of finned tube in a multipass shell and tube heat exchanger? Tube side pressure drop and the heat transfer rate Convective heat transfer co-efficient All of these Effective tube surface area for convective heat transfer Tube side pressure drop and the heat transfer rate Convective heat transfer co-efficient All of these Effective tube surface area for convective heat transfer ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) K/h0 h0/2K h0/K 2K/h0 K/h0 h0/2K h0/K 2K/h0 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Three solid objects of the same material and of equal mass-a sphere, a cylinder (length = diameter) and a cube are at 500°C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change in temperature is the smallest for Equal for all the three Cylinder Cube Sphere Equal for all the three Cylinder Cube Sphere ANSWER DOWNLOAD EXAMIANS APP
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