Heat Transfer Which of the following situations can be approximated to a steady state heat transfer system? A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmosheric air at 35°C A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C 10 kg of dry saturated steam at 8 kgf/cm² flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmosheric air at 35°C A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C 10 kg of dry saturated steam at 8 kgf/cm² flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In a laboratory test run, the rate of drying was found to be 0.5 x 10-3 kg/m².s, when the moisture content reduced from 0.4 to 0.1 on dry basis. The critical moisture content of the material is 0.08 on a dry basis. A tray dryer is used to dry 100 kg (dry basis) of the same material under identical conditions. The surface area of the material is 0.04 m²/kg of dry solid. The time required (in seconds) to reduce the moisture content of the solids from 0.3 to 0.2 (dry basis) is 6000 2000 4000 5000 6000 2000 4000 5000 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer With the increase of temperature, the Col-burn jH factor Decreases Increases Remains unchanged May increase or decrease ; depending on temperature Decreases Increases Remains unchanged May increase or decrease ; depending on temperature ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Water always boils when its Saturated vapour pressure is less than the atmospheric pressure Temperature reaches 100° C Saturated vapour pressure equals the external pressure on its surface Vapour pressure equals 76 cm of Hg Saturated vapour pressure is less than the atmospheric pressure Temperature reaches 100° C Saturated vapour pressure equals the external pressure on its surface Vapour pressure equals 76 cm of Hg ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe ) 2K/h0 hi/K K/h0 2hi/K 2K/h0 hi/K K/h0 2hi/K ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Prandtl number is the ratio of Thermal diffusivity to mass diffusivity Momentum diffusivity to thermal diffusivity Momentum diffusivity to mass diffusivity Thermal diffusivity to momentum diffusivity Thermal diffusivity to mass diffusivity Momentum diffusivity to thermal diffusivity Momentum diffusivity to mass diffusivity Thermal diffusivity to momentum diffusivity ANSWER DOWNLOAD EXAMIANS APP
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