AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
When red litmus paper is dipped in a base, it turns blue.
Source: Chapter 2, Section 2.1.1
This is a standard 1-mark factual question. Examiners expect just the colour change: red → blue. Remember the simple rule: bases turn red litmus blue; acids turn blue litmus red. No extra explanation is needed for 1 mark.