Question

Which of the following has the minimum unit weight?

(a) Dry sand

(b) Wet sand

(c) Damp clay

(d) Ordinary sand

The question was posed to me in a national level competition.

This is a very interesting question from Forces and Loads on Sewer in section Construction of Sewers, Sewer Appurtenances and Sewage Pumping of Environmental Engineering

Answer 1

Correct answer is (a) Dry sand

To explain: The unit weight of wet sand, damp clay, ordinary sand and dry sand are  1920kg/m^3, 1920kg/m^3, 1840kg/m^3 and  1600kg/m^3 respectively.