What effect does increasing steam pressure have on a steam turbine's efficiency?

Increasing steam pressure in a steam turbine generally enhances the efficiency of the turbine. This occurs because higher steam pressure results in a higher temperature of the steam, which in turn increases the thermal energy available for conversion into mechanical energy.

When steam enters the turbine at a higher pressure, it can expand more effectively, leading to greater energy extraction throughout the expansion process. This improved energy extraction means that the turbine can convert a larger portion of the energy from the steam into useful work, thereby enhancing overall efficiency.

Additionally, operating at higher pressures tends to allow for more advantageous thermodynamic cycles, such as improved heat ratios in Rankine cycles, which further contribute to the efficiency gains. Higher pressures also reduce the moisture content in the steam as it expands, which minimizes efficiency losses associated with wet steam damaging turbine blades.

In summary, the correct choice highlights the positive impact of increased steam pressure on the efficiency of steam turbines, capitalizing on greater energy extraction capabilities and improved thermodynamic performance.