Question

The correct sequence of energy changes in hydroelectric power station is:
A. kinetic to potential to mechanical to electrical
B. potential to kinetic to mechanical to electrical
C. potential to electrical to mechanical
D. potential to electrical to kinetic to mechanical

Answer 1

To answer this particular question we must know the working and process carried out in a Hydroelectric power station. From that we can discover which energy is converted into which and by studying that process in a hydroelectric power station we can tell the sequence in which these energies are converted. We know that hydroelectric power stations work on the principle of converting mechanical energy into electrical energy.

Complete answer:
The plant where electric energy is generated using water to propel a turbine is called the hydroelectric power plant. So as the name suggests water is used to propel the turbines. At first, the flowing water is stored across the dams. Which means that the kinetic energy of flowing water is stored as potential energy on the dams. Later, this stored water is made to fall on the turbines. This process is done to rotate the turbines, in other words the potential energy of water is used to turn the turbines which is a mechanical process. Therefore, the potential energy is converted into mechanical energy. At last, the rotating turbines generate electricity for later use. This final process is mechanical energy converted into electrical energy. So, from this we can conclude that the correct sequence in a hydroelectric power station is kinetic energy converted to potential, which is later converted to mechanical energy. This mechanical energy is used to generate the required electrical energy.

Therefore, the correct answer is option A.

Additional Information:
About a quarter part of energy used by the whole world is generated by the hydroelectric power stations. Among all the hydroelectric power stations Three Gorges Dam in China situated on Yangtze river is the largest in the world.

Note:
A shortcut to solve this question is to eliminate the options. We know that hydroelectric power stations are used to generate electricity. That means at the end of the process the last energy that will be given ads output will be electrical. So, option C and D can be eliminated. We also know that potential energy can not be created; it needs to be stored from previously produced energy. This eliminates option B and gives us the answer.