Heat Transfer A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300°C and allowed to cool in natural air. Which one will cool the slowest ? All of these Plate Cube Sphere All of these Plate Cube Sphere ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The purpose of providing expansion bellows in the shell of tubular exchanger is to Increase the heating load Facilitate increase of shell length, if needed Account for the uneven expansion of shell and tube bundles Impart structural strength Increase the heating load Facilitate increase of shell length, if needed Account for the uneven expansion of shell and tube bundles Impart structural strength ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions ? Assume that the conductive heat transfer co-efficient is infinitely large. 10 minutes 40 minutes 5 minutes 20 minutes 10 minutes 40 minutes 5 minutes 20 minutes ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Which of the following has the lowest overall heat transfer co-efficient? Water Molten sodium Air Dowtherm Water Molten sodium Air Dowtherm 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/K 2K/h0 h0/2K K/h0 h0/K 2K/h0 h0/2K ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The heat flux in the nucleate boiling regimes is proportional to (where, ΔT = excess temperature) √(ΔT) (ΔT)⁴ (ΔT)³ (ΔT)² √(ΔT) (ΔT)⁴ (ΔT)³ (ΔT)² ANSWER DOWNLOAD EXAMIANS APP