The purpose of nozzles in the turbine is to:

The primary purpose of nozzles in a turbine is to increase steam velocities. In a steam turbine, nozzles play a critical role in converting the thermal energy of steam into kinetic energy. As steam passes through the nozzle, its pressure decreases while its velocity increases significantly. This acceleration of steam is crucial because it directly influences the overall efficiency and performance of the turbine.

By transforming the steam's thermal energy into high-speed jets, the nozzles enable the steam to strike the turbine blades with greater force, thereby leading to improved rotational energy transfer. This process helps in generating more power from the same amount of steam input, making the turbine operate more effectively.

In contrast, options focusing on preventing noise, controlling cooling water flow, or maintaining pressure do not align with the fundamental function of nozzles. Noise mitigation and cooling systems are relevant to overall turbine operation but do not directly relate to the nozzle's primary role in enhancing steam velocity. Maintaining pressure is essential for turbine operation, but it is primarily managed through other components in the system rather than being a function of the nozzles themselves.