UPSC Prelims 2020 — practice paper

The official UPSC answer key for the Civil Services Preliminary Examination 2020 lists this as Set‑A Q100 with option C as correct. Statements 1 and 3 are true: biochar is used as a component in soilless/vertical farming media, and owing to its high porosity and surface area it improves the medium’s water‑holding capacity. Statement 2 was not accepted—claims that biochar specifically promotes nitrogen‑fixing microorganisms are context‑ and species‑dependent and were not considered universally valid for this question in 2020 (hence excluded in the key). See UPSC ‘AnsKey‑CSP‑20‑Paper‑I‑091121’ and the Set‑A paper showing Q100 is the biochar question.

Article 17 of the Constitution explicitly abolishes “untouchability” and forbids its practice in any form. Article 17 is located within the Right to Equality grouping of Fundamental Rights (Articles 14–18) in Part III. Therefore, protection against untouchability is incorporated under the Right to Equality. (Legislative Dept. text of Article 17; Know India–National Portal; PIB Constitution e-book p.71).

Sec. 12(h) of the Legal Services Authorities Act, 1987 entitles persons below the notified income ceiling to free legal aid; States fix this ceiling for subordinate courts (e.g., Delhi lists “a person with annual income < ₹1,00,000”). Several State LSAs also expressly cover transgender persons subject to an income cap (Delhi: transgender with annual income < ₹2,00,000). OBC status per se is not an eligibility category under Sec. 12; an OBC becomes eligible only if covered by other clauses like the income ceiling, so the ₹3,00,000 blanket is incorrect. “All senior citizens” is wrong: NALSA clarifies that senior-citizen eligibility depends on State rules and often has an income limit. Hence, 1 and 2 are true; 3 and 4 are false.