Question

A U tube contains water and methylated spirit separted by mercury. The mercury colums in the tow arms are at the same level with 10 cm of water in one are and 12.5 cm of spirit in the other as shown in figure. The relative density of the spirit is
A. 0.6
B. 0.8
C. 1
D. 1.25

Answer 1

Correct Answer - B
(b) Refer figure. As the mercury columns in the two arms of U tube are at the same level, therefore Pressure due to water = Pressure due to spirit colum
`rho w_h w_g = rho_gh_g`
`rho_s = (h_w)/(h_s)rho_w`
:. Relativedensity of spirit ` = (rho_s)/(rho_w) = (h_w)/(h_s) = (10cm)/(12.5cm) = 0.8`