Heat Transfer The absorptivity of a grey body at a given temperature __________ with increasing wavelength of radiation. Remains constant Decreases May increase or decrease ; depends on the material Increases Remains constant Decreases May increase or decrease ; depends on the material Increases ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Presence of a non-condensing gas in a condensing vapour None of the listed here is desirable to increase the film co-efficient decreases thermal resistance increases the rate of condensation None of the listed here is desirable to increase the film co-efficient decreases thermal resistance increases the rate of condensation ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer 1 BTU/hr.ft.°F is equal to __________ kcal/hr. m.°C. 1 1.49 None of these 4.88 1 1.49 None of these 4.88 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 40 minutes 5 minutes 10 minutes 20 minutes 40 minutes 5 minutes ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Baffle spacing Should be less than one fifth the diameter of the shell Is not the same as baffle pitch None of these Should be less than the inside diameter of the shell Should be less than one fifth the diameter of the shell Is not the same as baffle pitch None of these Should be less than the inside diameter of the shell ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In a heat exchanger, floating head is provided to increase log mean temperature gradient increase the heat transfer area facilitate cleaning of the exchanger relieve stresses caused by thermal expansion increase log mean temperature gradient increase the heat transfer area facilitate cleaning of the exchanger relieve stresses caused by thermal expansion ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS