Question

Which method is used to produce electricity in hydroelectric power plants?
A) By Boiling the water to produce steam
B) By ionization of water
C) By running dynamo with Kinetic Energy of water
D) By running dynamo with Potential Energy of water

Answer 1

Hint: The production of electricity by the motion of water running through electrical generators is in simple terms is known as hydroelectric power. The method comprises water flowing either from a river or canal and throwing it from a certain height on the generator or the dynamo to create electricity.

Complete step by step solution:
Before checking the options, let us define how electricity is formed in hydroelectric dams. The water is the energy medium in this case or the mass for the energy formula and when the water/mass which when fall on the turbine generator possess a potential energy which when falling on the generator is converted into kinetic energy, the kinetic energy which move the turbine or the wheels (structure of the turbine generator) of the electrical generator in turn converting mechanical energy (sum of potential and kinetic energy) into electrical energy.

Now when the water is taken to a certain height before moving onto the wheels it is potential energy as the water hasn't fallen on the wheel but when the water falls on the wheel at a certain velocity, most of the energy of the falling water is converted from potential energy to kinetic energy. Hence, option (A), (B) and (D) are false and the correct option is (C) as kinetic energy is needed to move the turbine at a certain speed to generate the electricity by overcoming the threshold conditions.

Note: The potential energy of the water is given by the formula of \[P.E.=mgh\] and the kinetic energy as \[K.E.=0.5m{{v}^{2}}\]. The boiling of water produces steam which lifts heavy objects forming hydraulic energy and ionization of water produces hydronium ions.