The turbine nozzles convert heat and pressure energy to velocity energy by means of which of the following?

Correct Answer: Option D — Convergent process.

Turbine nozzles function as convergent ducts that accelerate the gas flow. By restricting the cross-sectional area, the nozzle increases the velocity of the working fluid while simultaneously decreasing its pressure and temperature, effectively converting internal energy into the kinetic energy required to drive the downstream rotating turbine blades.