Question

In hydroelectric power plants, _ _ _ _ of flowing water changes to _ _ _ _ _.
A. Potential energy, kinetic energy respectively
B. Kinetic energy, potential energy respectively
C. Potential energy, aquatic energy respectively
D. Kinetic energy, thermal energy respectively

Answer 1

Hint: As the name suggests, in a hydroelectric power plant, electrical energy is produced by utilizing the hydraulic energy of water. The hydraulic energy of water is converted into mechanical energy of the turbine used in the power plant, and that mechanical energy is further converted into mechanical energy.

Complete step by step answer:The water to be used in the hydroelectric power plant is stored at a certain height due to which it has potential energy which is also known as energy due to the head of water. We allow the water stored in the reservoir to flow through the vanes of the turbine due to which the impeller of the turbine rotates.

We can see that initially, water has potential energy, due to the flow of water it is converted into kinetic energy which is utilized in the production of electricity.

Therefore, we can say that in a hydroelectric power plant, the potential energy of flowing water changes to kinetic energy.
Hence option (A) is correct.

Additional information: In a reaction turbine, at the exit, we use a draft tube to discharge water into the atmosphere so that the potential energy of water can be utilized entirely and to make the exit pressure more than or equal to atmospheric pressure.

Note:The energy of water at the inlet of the turbine can be kinetic energy completely or the combination of kinetic and potential energy both. The turbine having inlet energy as kinetic only is called an impulse turbine, and the turbine having a combination of both energies at the inlet is called a reaction turbine.