A U tube contains water and spirit separated by mercury. The mercury columns in the two arms are in

Question

A U tube contains water and spirit separated by mercury. The mercury columns in the two arms are in level with 10 cm of water in one arm and 12.5 cm of spirit in the other. Then the relative density of the spirit is

Professor PC Thomas Classes · Answer

Equating pressure at mercury level: $ho_w g h_w = ho_s g h_s \implies 1 	imes 10 = ho_s 	imes 12.5 \implies ho_s = 0.8$.