Steam Boilers, Engines, Nozzles and Turbines The efficiency of an impulse turbine is maximum when (where Vb = Blade speed, V = Absolute velocity of steam entering the blade, and α = Nozzle angle) Vb = V cosα Vb = 0.5 V cosα Vb = V² cosα Vb = 0.5 V² cosα Vb = V cosα Vb = 0.5 V cosα Vb = V² cosα Vb = 0.5 V² cosα ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines Caking coals are those which Burn freely Form lumps or masses of coke Burn completely Show little or no fusing action Burn freely Form lumps or masses of coke Burn completely Show little or no fusing action ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines In a velocity compounded impulse turbine, when steam flows through the second row of moving blades, Pressure remains constant Velocity remains constant Velocity decreases Velocity increases Pressure remains constant Velocity remains constant Velocity decreases Velocity increases ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines Hard coke is produced by carburization of coal at Atmospheric temperature 950-1100°C 700-850°C 500-600°C Atmospheric temperature 950-1100°C 700-850°C 500-600°C ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The air pressure at the fuel bed is reduced below that of atmosphere by means of a fan placed at or near the bottom of the chimney to produce a draught. Such a draught is called Induced draught Natural draught Balanced draught Forced draught Induced draught Natural draught Balanced draught Forced draught ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The ratio of the workdone on the blades to the energy supplied to the blades, is called Gross or stage efficiency Mechanical efficiency Blading efficiency Nozzle efficiency Gross or stage efficiency Mechanical efficiency Blading efficiency Nozzle efficiency ANSWER DOWNLOAD EXAMIANS APP
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