Question

A cheap, conventional, commercial and inexhaustible source of energy is
a) Hydropower
b) Solar energy
c) Wind energy
d) Thermal energy

Answer 1

Hint: The energy derived from the falling of water at high pressure with the greater force which can be through a river, dam, etc.

Complete answer
Hydropower is the generation of the power from energy utilized during fast-running water in rivers and dams. It is the most common method of electricity production. Thus, hydropower is one of the cheapest, conventional and inexhaustible sources of energy as water renewal depends on the water cycle unlike the fossil fuels which get exhausted, can not be recycled and does not require special machinery and set up for its extraction.

Additional information
-Hydropower became a source of energy during the late nineteenth century.
-The main application of hydropower is to generate electricity which is known as hydroelectricity.
-The hydroelectric power plants include a reservoir to use the energy of the falling water to produce hydroelectricity, most common in the case of dams.
-It may be used to store potential energy between the two reservoirs.
-Solar energy is a form of radiant energy which is obtained from the sun and is an essential source of renewable energy.
-Wind energy is the use of wind to provide mechanical power through wind turbines turned into electric generators. Wind power is sustainable and renewable energy.
-Thermal energy is associated with the heat. It refers to various physical concepts, such as the internal energy of a system; heat or sensible heat, these are all types of energy transfer.

So, the correct answer is ‘Hydropower’.

Note: The first house which was powered by hydroelectricity was Cragside in Northumberland in 1878. At Niagara Falls, the first commercial hydroelectric power plant was built in 1879. At Niagara Falls, the street lamps were lighted and the electricity was generated by the hydropower in 1881.