Question

A liquid $X$ of density $ 3.36\text{ }g/c{{m}^{3}} $ is poured in a U-tube, which contains $Hg$. Another liquid $Y$ is poured in left arm with height $8 \,cm$, upper levels of $X$ and $Y$ are same. What is the density of $Y$?

• A. 0.8 g/cc
• B. 1.2 g/cc
• C. 1.4 g/cc
• D. 1.6 g/cc

Answer 1

Answer: (A)

As shown in figure, in the two arms of a tube pressure remains same on surface $P P'$. Hence,
$8 \times \rho_{Y} \times g+2 \times \rho_{ Hg } \times g$
$=10 \times \rho_{X} \times g$

$\therefore \quad 8 \rho_{Y}+2 \times 13.6=10 \times 3.36$
or $\rho_{Y} =\frac{33.6-27.2}{8} $
$=0.8 \,g / cc$