🔍 Key Concepts

• Convergent nozzle vs. convergent-divergent nozzle and what happens to steam velocity and pressure in each section • Behavior of steam (a compressible fluid) when it passes through a restriction and then an expanding passage • Relationship between velocity, pressure, and specific volume for expanding steam

💭 Think About

• Think about what happens to steam as it passes through the throat (smallest area) of the nozzle and then into the diverging section: does it speed up or slow down? • If steam is expanding through the nozzle, does its pressure go up or down? What usually happens to specific volume when steam expands? • Which of the choices matches the typical purpose of a nozzle on a steam turbine: to produce high force, or to change direction, or to compress steam?

✅ Before You Answer

• Be clear on whether a nozzle normally increases or decreases velocity of steam feeding a turbine • Decide whether expansion of steam is associated with a rise or a drop in pressure • Check if the option you’re considering would make sense for driving a turbine that needs high-velocity steam jets