In India, most of the major coalfields such as Jharia, Raniganj, and Bokaro are located in the valley of which of the following rivers?

Introduction / Context:
India's coal resources are crucial for power generation and heavy industry. Many competitive exams ask about the location of major coalfields and the river valleys in which they are found. This question focuses on the classic coalfields in eastern India and tests whether you remember the river valley associated with them.

Given Data / Assumptions:

• We are concerned with major coalfields such as Jharia, Raniganj, and Bokaro.
• We need to identify the river valley where these coalfields are mainly located.
• Options mention Damodar, Godavari, Mahanadi, and Wardha rivers.

Concept / Approach:
The Damodar river flows through Jharkhand and West Bengal and is historically known as the Ruhr of India because of its rich coal deposits and industrial activity. The famous coalfields of Jharia, Raniganj, Bokaro, and others are located in the Damodar valley region. Other river valleys like Godavari and Mahanadi also have coal deposits, but the specific classic coal belt associated with the earliest industrialisation in India is the Damodar valley.

Step-by-Step Solution:
Step 1: Recall that Jharia, Raniganj, and Bokaro coalfields are in eastern India, particularly Jharkhand and West Bengal.Step 2: Remember that the Damodar river flows through this region and that the Damodar valley has extensive coal deposits.Step 3: Associate the phrase Ruhr of India with the Damodar valley due to coal and industry.Step 4: Check the other options and note that they correspond to other regions not primarily associated with these particular coalfields.Step 5: Conclude that the coalfields mentioned are mainly located in the Damodar river valley.

Verification / Alternative check:
Standard geography references list the Damodar valley as the most important coal bearing region of India with classic coalfields such as Jharia and Raniganj. The Damodar Valley Corporation was set up in this region for river valley development, power generation, and flood control, underlining the economic importance of this coal rich belt.

Why Other Options Are Wrong:
Godavari: The Godavari valley has coal deposits, especially in the Singareni coalfields, but those are different from the classic eastern coal belt mentioned in the question.
Mahanadi: This river flows mainly through Chhattisgarh and Odisha, and while the region has minerals, it is not the main location of Jharia or Raniganj coalfields.
Wardha: Wardha valley in central India also has coal deposits, but again it is different from the Damodar valley coal belt described in the question.

Common Pitfalls:
Students sometimes mix up different coal belts because many river valleys in India have some coal deposits. A reliable memory trick is to connect Damodar valley with the phrase Ruhr of India and with classic coalfields like Jharia and Raniganj. This makes it easier to select Damodar quickly in exams.

Final Answer:
The major coalfields such as Jharia and Raniganj are located in the Damodar river valley.