Question 591Steam Plants - Assistant Engineer

The correct answer is A) moving and fixed blades being shaped to act as nozzles. In a reaction turbine, the moving and fixed blades are designed to act as nozzles, which accelerates the flow of the working fluid (such as steam) and creates a pressure drop across both sets of blades. This pressure drop is a result of the velocity increase caused by the nozzle-like shape of the blades, which converts the thermal energy of the fluid into kinetic energy. The other options are incorrect because: B) reversing blades do not necessarily cause a pressure drop, C) interstage diaphragms are not the primary cause of the pressure drop, and D) the conversion of thermal energy to pressure energy does not always result in a pressure drop in a reaction turbine.