question_answer

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

Correct Answer: A

Solution :

 As shown in figure, in the two arms of a tube pressure remains same on surface PP. Hence, \[8\times {{p}_{Y}}\times g+2\times {{p}_{Hg}}\times g=10\times {{p}_{x}}\times g\] \[\therefore \] \[8{{p}_{Y}}+2\times 13.6=10\times 3.36\] Or \[{{p}_{Y}}=\frac{33.6-27.2}{8}\] \[=0.8g/cc\]