Explanations:Lignite is a type of coal that is formed from partially decomposed plant matter. It is the lowest rank of coal and has a lower energy content compared to other types of coal such as bituminous or anthracite. Lignite is primarily used for power generation and is an important resource for many countries, including India.
In India, lignite deposits are found in several states, but not all of these deposits are economically exploitable. Economically exploitable lignite refers to deposits that can be mined and utilized in a cost-effective manner, taking into account factors such as the quality of the lignite, the depth at which it is found, and the infrastructure available for mining and transportation.
Tamil Nadu is one of the states in India that has significant economically exploitable lignite deposits. The Neyveli Lignite Corporation (NLC) is a major player in the lignite mining industry in Tamil Nadu. The Neyveli region, located in the Cuddalore district of Tamil Nadu, is known for its lignite deposits, which have been mined since the 1950s. The lignite from this region is used primarily for power generation in thermal power plants.
Other states in India, such as Andhra Pradesh, Karnataka, and Kerala, do not have significant economically exploitable lignite deposits. These states may have other mineral resources, but they are not known for lignite. Therefore, the correct answer to the question is Tamil Nadu, as it is the state with significant economically exploitable lignite deposits.