Question

In a hydraulic power station, water is first stored in a dam at a higher altitude.

1. What is the purpose of being stored at higher altitudes?
2. When the water is allowed to fall on a turbine, what change of energy takes place for the water?
3. Why is this turbine connected to the armature of a generator?
4. Which basic law of physics is followed by the whole mechanism?

Answer 1

1. Water is stored at a higher altitude so that it has gravitational potential energy, given by (U = mgh). This stored energy can be used to do work when the water is released.
2. As the water falls, its gravitational potential energy is converted into kinetic energy. The moving water then turns the turbine, giving it mechanical energy.
3. The turbine is connected to the generator’s armature so that its rotation drives the generator. The generator converts this mechanical energy into electrical energy by electromagnetic induction.
4. The mechanism follows the law of conservation of energy; energy is not created or destroyed, but is transformed from gravitational potential energy into kinetic energy, mechanical energy and finally electrical energy.