120) The critical pressure ratio is given by (where p₁ = Initial pressure of steam, and p₂ = Pressure of steam at throat or critical pressure)

121) 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

122) 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.

123) Stage efficiency is also known as

124) A single stage turbine is not used because it requires large reduction gearing due to very high rotational speed.