10th January 2025

Explanation:
All pairs are correctly matched:
Quantum dots are used to improve solar cell efficiency by capturing a broader spectrum of light.
Graphene is utilized in supercapacitors for energy storage due to its high surface area and conductivity.
Nanostructured catalysts enhance hydrogen production by increasing the efficiency of water splitting reactions.
Carbon nanotubes are used as thermoelectric materials for waste heat recovery due to their unique thermal and electrical properties.

Explanation: Statements 1 and 3 are correct. Gravitational lensing can indeed cause a single object to appear at multiple points in the sky and can amplify the light from background objects1.  However, statement 2 is incorrect. While galaxy clusters can act as gravitational lenses, they are not the only celestial bodies that can cause this phenomenon. Any massive object, including individual galaxies and even stars, can produce gravitational lensing effects.

Explanation: Both statements are incorrect. AnemiaPhone uses a small finger stick to obtain a drop of blood, which is then analyzed using a test strip similar to a COVID-19 home test. The technology does not utilize spectrophotometric analysis, nor does it require a venous blood draw. Instead, it employs a rapid screening method that can be interpreted by healthcare workers on the spot.

Explanation: All three statements are correct. The Uttarakhand High Court has criticized authorities for unregulated soapstone mining in Bageshwar district. Soapstone mining has been linked to land subsidence issues in regions like Joshimath, as mentioned in the context of mining impacts on stability and ecosystems. The absence of a clear definition for "semi-mechanized mining" by both the State of Uttarakhand and the Union of India has led to environmental clearances being granted without defined policy limits.

Explanation: Only statement 4 is correct. The ITBP operates border outposts at altitudes ranging from 9,000 feet to 18,750 feet1. Statement 1 is incorrect; ITBP was initially raised under the CRPF Act, not the BSF Act. Statement 2 is incorrect; while ITBP guards a significant portion of the India-China border, it does not cover the entire length. Statement 3 is incorrect; while many ITBP personnel are trained mountaineers and skiers, it is not a requirement for all personnel.