Which way does steam flow in a turbine?

In a turbine, steam primarily flows to the nozzles. This flow is a critical part of the turbine's operation. The design of the turbine is such that steam enters through the nozzles where it expands and accelerates. This expansion converts thermal energy into kinetic energy, which is then harnessed to turn the turbine blades.

Once the steam has accelerated through the nozzles, it impacts the blades of the turbine, causing them to rotate. This rotation is what produces mechanical energy that can be used to drive generators or other equipment. The nozzle's shape is designed to maximize the steam's velocity and direct it effectively toward the turbine blades, ensuring efficient power generation.

The other options highlight scenarios that do not accurately reflect the intended function of a turbine. For example, steam does not flow passively to the exhaust, nor does it move randomly throughout the system, as doing so would lead to inefficiencies in energy production. Additionally, steam does not reverse through the throttling valve; throttling is intended to regulate steam flow and pressure, not to create a reverse flow. Therefore, the correct answer focuses on the directed flow of steam towards the nozzles, which is essential for the turbine's proper functioning and energy conversion processes.