Explanations:The question asks about the largest dam in Tamil Nadu that is built across the Kaveri river. To understand this, it is important to know the geography and infrastructure of Tamil Nadu, particularly the major dams and their locations.
The Kaveri river, also known as the Cauvery river, is one of the major rivers in southern India, flowing through the states of Karnataka and Tamil Nadu. It is a significant source of water for irrigation, drinking, and hydroelectric power generation. The Mettur dam, also known as the Stanley Reservoir, is the largest dam in Tamil Nadu and is built across the Kaveri river. It is located in the Erode district of Tamil Nadu and was constructed in 1934.
The Mettur dam is a masonry gravity dam and is primarily used for irrigation, hydroelectric power generation, and flood control. It has a length of about 1,400 meters and a height of 48 meters. The reservoir created by the dam, the Stanley Reservoir, has a capacity of about 1,000,000 acre-feet of water. The dam is a crucial part of the Kaveri river management system and plays a significant role in the agricultural and economic development of the region.
Other large dams mentioned in the options, such as the Bhakra-Nangal dam, Nagarjuna Sagar dam, and Hirakud dam, are located in different states of India and are not relevant to the context of the question. The Bhakra-Nangal dam is in Punjab and Himachal Pradesh, the Nagarjuna Sagar dam is in Andhra Pradesh, and the Hirakud dam is in Odisha. These dams are significant in their respective states but are not the largest dams in Tamil Nadu.
Therefore, the correct answer is the Mettur dam, which is the largest dam in Tamil Nadu and is built across the Kaveri river. Understanding the geographical and infrastructural details of the region is crucial for answering such questions accurately.