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 = 0.5 V cosα Vb = 0.5 V² cosα Vb = V cosα Vb = V² cosα Vb = 0.5 V cosα Vb = 0.5 V² cosα Vb = V cosα Vb = V² cosα ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The flow through a nozzle is regarded as Isothermal flow Constant volume flow Constant pressure flow Isentropic flow Isothermal flow Constant volume flow Constant pressure flow Isentropic flow ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The critical pressure ratio is given by (where p₁ = Initial pressure of steam, and p₂ = Pressure of steam at throat or critical pressure) p₁/p₂ p₁ + p₂ p₁. p₂ p₂/p₁ p₁/p₂ p₁ + p₂ p₁. p₂ p₂/p₁ ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The missing quantity per stroke is equal to Mass of cushion steam + cylinder feed Mass of cushion steam + indicated mass of steam Cylinder feed + indicated mass of steam Cylinder feed indicated mass of steam Mass of cushion steam + cylinder feed Mass of cushion steam + indicated mass of steam Cylinder feed + indicated mass of steam Cylinder feed indicated mass of steam ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of Fouling of heat transfer surfaces Higher effectiveness of boiler Raising of steam temperature High calorific value coal being burnt Fouling of heat transfer surfaces Higher effectiveness of boiler Raising of steam temperature High calorific value coal being burnt ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines Lancashire boiler is used where working pressure and power required are Low Moderate High None of these Low Moderate High None of these ANSWER DOWNLOAD EXAMIANS APP
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