Match List I with List II and select the correct answer using the code given below the Lists :
| List I (Isotope) |
List II (Application) |
|---|---|
| A. Carbon | 1. Treatment of goitre |
| B. Cobalt | 2. Calculation of age of the earth |
| C. Iodine | 3. Treatment of cancer |
| D. Uranium | 4. Fuel in nuclear reactors |
Code :
2 3 1 4
2 1 3 4
4 1 3 2
4 3 1 2
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CAPF – 2016
– C. Iodine (specifically Iodine-131) is used in the diagnosis and treatment of thyroid conditions, including goitre, as the thyroid gland absorbs iodine. This matches with application 1.
– D. Uranium (specifically Uranium-235) is the primary fuel used in nuclear reactors for generating energy through nuclear fission. Uranium isotopes (like Uranium-238) are also used in radiometric dating (Uranium-Lead dating) to calculate the age of rocks and the Earth. Application 4 (Fuel in nuclear reactors) and Application 2 (Calculation of age of the earth) are both valid uses of Uranium isotopes.
– A. Carbon: Carbon-14 is used for radiocarbon dating, but this is for dating organic materials up to around 50,000 years old, not for the age of the Earth itself (which is billions of years, dated using isotopes like Uranium). Carbon (graphite) is used as a moderator in some nuclear reactors, but not as fuel. Neither application 2 nor 4 is a direct or primary application of Carbon isotopes compared to other options.
Let’s examine the pairings in option D: A-4 (Carbon for Fuel), B-3 (Cobalt for Cancer), C-1 (Iodine for Goitre), D-2 (Uranium for Age of Earth). B-3, C-1, and D-2 are correct pairings. A-4 is incorrect as Carbon is a moderator, not fuel, in reactors.
Both option A and D contain correct pairings for B and C. Both contain a correct pairing for D (either 2 or 4, as both are valid uses). Both contain an incorrect pairing for A. Comparing the incorrect pairings for A, linking Carbon-14 dating to ‘Age of Earth’ might be considered slightly less incorrect in the context of general dating methods related to Earth’s history than linking Carbon (as moderator) to ‘Fuel’. Therefore, option A (A-2, B-3, C-1, D-4) is the most likely intended answer, despite the flaw in the A-2 pairing.