2022 P2 Q81
Q1. In swimming pools, the free residual chlorine required for providing adequate protection against bacterial and viral agents should be:
- 0·5 mg/litre
- 1·0 mg/litre
- 1·5 mg/litre
- 2·0 mg/litre
Answer & explanation — reveal it in the interactive practice above.
PYQ 2020–2025 — page 198
2023 P2 Q86
Q2. The ‘Nalgonda Technique’ developed by the National Environmental Engineering Research Institute (NEERI) was developed primarily for the removal of which one of the following from water?
- Asbestos
- Fluorine
- Chlorine
- Iron
Answer & explanation — reveal it in the interactive practice above.
PYQ 2020–2025 — page 265
