working of hydroelectric power plants

Answer 1

This question is vague, but here is the way hydro-electric power plants work.

Moving water turns a wheel or a turbine. The shaft of the water wheel or turbine is connected to an electric generator. As the generator spins, it produces electric energy.

The efficiency of this system depends on the speed of the water past the turbine blades. Efficiency can be increased, and more power produced, if the water speed is increased. A large dam can put the turbine blades several hundred feet below the surface of the lake and increase water speed.

A slow moving river can be used to produce electric power, but the main blade of the turbine (water wheel) has to be very large to produce torque. The shaft of the generator would be coupled to the large water-wheel through a set of gears that would increase the speed of the turbine shaft.

The electric generator has fixed magnets or electro-magnets installed on the rotor (part that spins). The stator (wire windings in the shell) produce electricity when the magnetic field from the rotor passes near them.