74051. In order to reduce the rotor speed of an impulse turbine, the method employed is
74052. The nozzle efficiency is the ratio of
74053. The friction in the nozzle __________ exit velocity of steam.
74054. In a reaction turbine
74055. A stage, in reaction turbine, is represented by
74056. When the nozzle operates with the maximum mass flow, the nozzle is said to be
74057. In a velocity compounded impulse turbine, when steam flows through the second row of moving blades,
74058. The ratio of the energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam is called mechanical efficiency.
74059. A steam nozzle converts
74060. The maximum discharge of steam through a convergent-divergent nozzle depends upon
74061. Steam turbines may be classified according to
74062. The process of draining steam from the turbine, at certain points during its expansion and using this steam for heating the feed water in feed water heaters and then supplying it to the boiler is known as
74063. In a 50% reaction turbine stage, tangential component of absolute velocity at rotor inlet is 537 m/s and the blade velocity is 454 m/s. The power output in kW of steam will be
74064. In an impulse turbine, steam expands
74065. In a nozzle, the effect of supersaturation is to increase the dryness fraction of steam.
74066. In a nozzle, the effect of supersaturation is to
74067. Which animal is known as ‘Flying Fox’?
74068. The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ number of stages are required.
74069. If the critical pressure ratio for steam is 0.546, then the steam is initially
74070. Step up or set down AC voltage which device is used?
74071. The maximum efficiency of a De-Laval turbine is (where α = Nozzle angle)
74072. The pressure compounded impulse turbine as compared to velocity compounded turbine require __________ number of stages.
74073. In a reaction turbine when the degree of reaction is zero, then there is
74074. The effect of friction in the nozzle __________ dryness fraction of steam.
74075. In a Parson's turbine stage, blade velocity is 320 m/s at the mean radius and rotor blade exit angle is 30°. For minimum kinetic energy of the steam leaving the stage, the steam velocity at the exit of the rotor will be
74076. In pressure compounding of an impulse turbine, the total pressure drop of the steam does not take place in the first nozzle ring, but is divided equally among all the nozzle rings.
74077. When the cross-section of a nozzle __________ continuously from entrance to exit, it is called a convergent nozzle.
74078. In an ideal impulse turbine, the
74079. During flow through a nozzle, no heat is supplied or rejected by the steam.
74080. In a reaction turbine, when steam flows through the moving blades,
74081. In velocity compounding of an impulse turbine, the expansion of steam takes place in a nozzle or a set of nozzles from the boiler pressure to condenser pressure.
74082. The critical pressure ratio is given by (where p1 = Initial pressure of steam, and p2 = Pressure of steam at throat or critical pressure)
74083. A steam turbine, in which a part of the steam after partial expansion, is used for process heating and the remaining steam is further expanded for power generation, is known as
74084. The stage efficiency is the ratio of energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam.
74085. Stage efficiency is also known as
74086. A single stage turbine is not used because it requires large reduction gearing due to very high rotational speed.
74087. In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is
74088. A nozzle is said to be a convergent-divergent nozzle, when the cross-section of a nozzle first decreases from its entrance to throat and then increases from its throat to exit.
74089. In an impulse reaction turbine, the pressure drops gradually and continuously over
74090. When the inlet pressure of steam is equal to the exit pressure, then
74091. The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades.
74092. The effect of bleeding is that
74093. The expansion of steam, as it flows over the blades in reaction turbine, represents
74094. The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.
74095. For a Parson's reaction turbine, if α1 and α2 are fixed blade angles at inlet and exit respectively and β1 and β2 are the moving blade angles at entrance and exit respectively, then
74096. 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)
74097. The velocity of whirl at outlet for an axial discharge turbine is
74098. In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is __________ the relative velocity of steam at inlet tip of the blade.
74099. The friction present between the steam and the nozzle surfaces reduces the heat drop by
74100. An impulse turbine as compared to a reaction turbine, for a given power has __________ row of blades.