🔍 Key Concepts

• Throttling process in steam systems (what happens to pressure, temperature, and enthalpy) • Difference between nozzles (where work/velocity change happens) and valves/orifices (where there may be no useful work) • Where in a steam turbine system steam can lose pressure without transferring energy to the rotor

💭 Think About

• In which option is steam experiencing a pressure drop but NOT driving the turbine wheel or blades to produce useful work? • Which components are specifically designed to convert pressure energy into kinetic energy to do work, and which are simply controlling or restricting flow? • Look for the choice that best matches a throttling device: does it mainly control flow/pressure, or does it convert energy into shaft work?

✅ Before You Answer

• Verify which component is acting as a control or restriction (throttle) rather than an energy-conversion device. • Check which option clearly mentions a pressure drop without the performance of work. • Eliminate choices that describe normal turbine work processes, like nozzle expansion driving blades, rather than throttling losses.