SSC SSC JE Civil 2025 Mock Test Series (Paper 1 & Paper 2) Environmental Engineering Water Treatment Filtration
In a slow sand filter, the effective size of sand varies from ______ to ______.
1
0.20 mm, 0.30 mm
2
0.5 mm, 0.75 mm
3
1 mm, 2 mm
4
0.1 mm, 15 mm