UPSC Civil Service Exam Questions - Engineering

Q1:

The dry density of a soil is 1.5 g/cc. If the saturation water content were 50%, then its saturated density and submerged density would, respectively, be

A 1.5 g/cc and 1.0 g/cc

B 2.0 g/cc and 1.0 g/cc

C 2.25 g/cc and 1.25 g/cc

D 2.0 g/cc and 1.50 g/cc

ANS:C - 2.25 g/cc and 1.25 g/cc

Given, rd = 1.5, w= 50%, rd=?,raub=?

Rd = rt/1+w
1.5 = rt/1+.5
1.5 * 1.5=rt
2.25 = rt => Ans

rsub = rsat-rw.
rsub = 2.25-1.
Raub = 1.25. Ans.