Mathura Refinery, which was commissioned in 1982 with a capacity of 6.0 MMTPA, is the how many th refinery of Indian Oil Corporation?

Introduction / Context:
Indian Oil Corporation has established several refineries across India to meet the growing demand for petroleum products. Each refinery has a specific commissioning year and order in the sequence of refineries set up by the company. Mathura Refinery, located in Uttar Pradesh, is one of the major refineries that came into operation in the early 1980s. This question asks you to recall which numbered refinery of Indian Oil Mathura Refinery was when it was commissioned in 1982 with a capacity of 6.0 million metric tonnes per annum (MMTPA).

Given Data / Assumptions:

• Mathura Refinery was commissioned in 1982.
• Its initial capacity was 6.0 MMTPA.
• We are asked which number refinery of Indian Oil it was (5th, 6th, 7th, or 8th).
• Basic knowledge of Indian Oil's refinery timeline is assumed.

Concept / Approach:
Indian Oil first set up refineries at locations like Guwahati, Barauni, Koyali, Haldia, and others before Mathura. By the time Mathura Refinery was commissioned, it became the sixth refinery in the sequence of Indian Oil refineries. This specific fact is often highlighted in company profiles and competitive exam material. Therefore, when the question links Mathura Refinery, the year 1982, and the capacity with a blank for which number refinery it was, the correct completion is that it was the sixth refinery of Indian Oil Corporation.

Step-by-Step Solution:

Verification / Alternative check:
You can verify this by mentally listing early Indian Oil refineries: Guwahati, Barauni, Koyali, Haldia, and others, before Mathura. Company publications and fact sheets often state explicitly that Mathura Refinery was the sixth refinery of Indian Oil. Checking this association in any reliable reference confirms that the correct option is 6th, not 5th, 7th, or 8th.

Why Other Options Are Wrong:

• 7th refinery of Indian Oil: Does not match the commonly documented sequence in which refineries were set up.
• 5th refinery of Indian Oil: Understates the number of refineries already in existence before Mathura was commissioned.
• 8th refinery of Indian Oil: Overstates the sequence and does not align with standard references regarding Mathura's order.

Common Pitfalls:
Because several refineries were set up over a few decades, some candidates find it difficult to remember the exact order and may guess. Another pitfall is confusing the number of refineries overall with Mathura's position in that sequence. To avoid such confusion, it helps to memorise a few key identifying facts, such as "Mathura – commissioned 1982 – sixth refinery of Indian Oil." This compact association aids quick recall during exams.

Final Answer:
Mathura Refinery, commissioned in 1982 with a capacity of 6.0 MMTPA, is the 6th refinery of Indian Oil.