GATE Civil Engineering (CE) 2019 Shift 1 Solved Paper

As we know that settling velocity for discrete particles is given by stokes law as
VT=‌

(G−1)γd2

18µ

⇒VT∝d2
For 30 second duration if 0.35mm particle size settles completely then % removal of particle size 0.45mm and 0.50mm will be 100% respectively for each. As settling velocity of particle size 0.45mm and 0.50mm will be greater than settling velocity of size 0.35mm(VT∝d2).