Question

A bottle is inverted and dipped into a tank. At the bottom of the tank, $(\frac{3}{5}{)}^{th}$th part of the bottle is filled with water. The depth of the tank is :

• A. 20 m
• B. 15 m
• C. 10 m
• D. 5 m

Answer 1

The correct option is B 15 m

SInce the volume of air in the bottle becomes $\frac{2}{5}$ times, pressure in it becomes $\frac{5}{2}$ time atmospheric pressure.

Hence pressure difference between gas in bottle and atmospheric pressure must be balanced by height of water in water tank,

Hence, $\frac{5}{2}\left({10}^5\right)-\left({10}^5\right)=\left(1000\right)\left(10\right)h$

This gives $h=15m$.