# In the figure, the cross-sectional area of the smaller tube is a and that of the larger tube is 2a….

Q: In the figure, the cross-sectional area of the smaller tube is a and that of the larger tube is 2a. A block of mass m is kept in the smaller tube having the same base area a, as that of the tube. The difference between water levels of the two tube is

(a) $\displaystyle \frac{P_0}{\rho g}+\frac{m}{a \rho}$

(b) $\displaystyle \frac{P_0}{\rho g}+\frac{m}{2 a \rho}$

(c) $\displaystyle \frac{ m}{a \rho }$

(d) $\displaystyle \frac{ m}{2 a \rho }$

Ans: (c)

Sol: $\large P_0 + \frac{m g}{a} = P_0 + \rho g h$

$\large \frac{m g}{a} = \rho g h$

$\displaystyle h = \frac{ m}{a \rho }$