Which one of the following is the highest gravity dam among the dams listed?

Introduction / Context:
Dams are important structures in geography and general knowledge, used for irrigation, power generation, and flood control. They can be classified by design, such as gravity dams, arch dams, and earthen dams. Some dams are particularly notable for their height. This question asks which dam among the given options is the highest gravity dam.

Given Data / Assumptions:

• The dams listed are Beas Dam, Nangal Dam, Bhakra Dam, and Hirakud Dam.
• We are specifically concerned with the height of the dam structure and the fact that it is a gravity dam.
• We assume standard textbook information on major Indian dams and their characteristics.

Concept / Approach:
Bhakra Dam, built on the Sutlej River, is one of the highest gravity dams in the world and has often been described in textbooks as the highest straight gravity dam at the time of its construction. It is significantly taller than Hirakud Dam, which is known more for its great length than height. Nangal Dam is a smaller dam downstream of Bhakra, and Beas Dam is not as high as Bhakra either. Thus, among the options, Bhakra Dam is the highest gravity dam.

Step-by-Step Solution:
Step 1: Recall key facts about Bhakra Dam, which is a concrete gravity dam on the Sutlej River with a substantial height.Step 2: Remember that Hirakud Dam on the Mahanadi River is very long and is famous as one of the longest earthen dams but is not as high as Bhakra.Step 3: Note that Nangal Dam is a smaller dam located downstream of Bhakra and does not match Bhakra in height.Step 4: Beas Dam is also not as high as Bhakra Dam when comparing structural heights.Step 5: From this comparison, Bhakra Dam clearly stands out as the highest gravity dam among the listed options.

Verification / Alternative check:
Geography books often highlight Bhakra Dam as a major engineering achievement in independent India and mention its impressive height. In contrast, Hirakud is typically highlighted for its length and reservoir capacity. Multiple exam questions and tables of major dams categorise Bhakra as one of the highest gravity dams, confirming that it is the correct answer here.

Why Other Options Are Wrong:
Beas Dam: An important dam but not remarkable for height in the way Bhakra is.

Nangal Dam: A smaller structure downstream of Bhakra, built mainly as a barrage and power station support, not the highest dam.

Hirakud Dam: Famous as a long dam across the Mahanadi River and known for its extensive reservoir, but it is not as high as the Bhakra gravity dam.

Common Pitfalls:
Some students confuse the length of a dam with its height and may select Hirakud because they recall it as a record holding dam. It is important to read the question carefully and focus on what is being asked. Height refers to the vertical dimension of the dam structure, while length refers to how long the dam extends along the river. Recognising that Bhakra stands out for height and Hirakud for length helps avoid this confusion.

Final Answer:
Bhakra Dam is the highest gravity dam among the dams listed.