Final answer:
The purpose of a turbine is indeed to convert the mechanical energy of a fluid into shaft work, which is then used to generate electricity. This statement is true, aligning with the principles of energy conversion in a turbine system.
Step-by-step explanation:
The statement "The purpose of a turbine is to convert the mechanical energy of the fluid into shaft work out" is true. A turbine does exactly this by transferring kinetic energy from a moving fluid, which could be water in hydropower installations or steam produced by burning fossil fuels, into rotational motion of the turbine's blades. This rotating motion is then used to turn a shaft, which in turn operates an electric generator to produce electricity. The electrical generator uses the relative motion between magnets and coils of wire to convert mechanical energy into electrical energy, functioning similarly to an electric motor running in reverse.
The efficiency of a turbine, or any other simple machine, is always less than 100 percent due to energy losses, primarily in the form of heat resulting from friction. Heat engines, which are different from electric generators, are devices that convert thermal energy into mechanical energy. Conversely, electric motors transform electrical energy into mechanical energy.