Heat Transfer In thermal radiation for a black body (where, ε is emissivity and α is absorptivity) α = 1; ε ≠ 1 α ≠ 1, ε ≠ 1 α ≠ 1, ε = 1 α = 1; ε = 1 α = 1; ε ≠ 1 α ≠ 1, ε ≠ 1 α ≠ 1, ε = 1 α = 1; ε = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer For gases, the thermal conductivity increases with temperature rise. For liquids, with increase in concentration, its thermal conductivity generally Increases Remains unchanged Decreases Increases exponentially Increases Remains unchanged Decreases Increases exponentially 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 20 minutes 5 minutes 40 minutes 10 minutes 20 minutes 5 minutes 40 minutes ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The average heat transfer co-efficient over the entire length of the plate (ha) and the local heat transfer co-efficient (hL), in case of heat transfer over a flat plate in lminar zone is related as Ha= 5hL Ha = 0.8hL Ha = 2hL Ha = hL Ha= 5hL Ha = 0.8hL Ha = 2hL Ha = hL ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Maximum heat transfer rate is obtained in __________ flow. Turbulent Creeping Laminar Transition region Turbulent Creeping Laminar Transition region ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In a backward feed multiple effect evaporator None of these Feed is introduced in the first effect Feed flows from low pressure to high pressure No pumps are required between successive effects None of these Feed is introduced in the first effect Feed flows from low pressure to high pressure No pumps are required between successive effects ANSWER DOWNLOAD EXAMIANS APP
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