Question

The average grain size of the bed material is 0.16 mm for medium silt, Lacey’s silt factor is likely to be _______

(a) 0.30

(b) 0.45

(c) 0.70

(d) 1.32

I had been asked this question by my college director while I was bunking the class.

I would like to ask this question from Culverts Construction topic in portion Culverts and Small Road Bridges Construction of Irrigation Engineering

Answer 1

Correct option is (c) 0.70

For explanation I would say: Lacey’s silt factor (f) is given by f = 1.76 d^1/2 where d is the average particle size in mm.

F = 1.76 (0.16)^1/2

F = 0.704.