Q. A monometer connected to a closed tap reads $4.5 \times 10^{5}\ pascal$. When the tap is opened the reading of the monometer falls to $4 \times 10^{5}\ pascal$. Then the velocity of flow of water is
A) $7\ ms^{- 1}$
B) $8\ ms^{- 1}$
C) $9\ ms^{- 1}$
D) $10\ ms^{- 1}$
Explanation
(d) $\frac{P_{1} - P_{2}\ }{\rho g} = \frac{v^{2}}{2g} \Rightarrow \frac{4.5 \times 10^{5} - 4 \times 10^{5}}{10^{3} \times g} = \frac{v^{2}}{2g}\ \therefore v = 10m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.