Physics · PYQ NEET UG 2019(1)
हिन्दीA small hole of area of cross-section \( 2\text{ mm}^2 \) is present near the bottom of a fully filled open tank of height \( 2\text{ m} \). Taking \( g = 10\text{ m/s}^2 \), the rate of flow of water through the open hole would be nearly:
Correct answer · Option 3
\( 12.6 \times 10^{-6}\text{ m}^3/\text{s} \)
Explanation
Velocity of efflux \( v = \sqrt{2gh} = \sqrt{2 \times 10 \times 2} = \sqrt{40} \approx 6.32\text{ m/s} \). Volume flow rate \( Q = A v = (2 \times 10^{-6}\text{ m}^2) \times 6.32\text{ m/s} = 1.264 \times 10^{-5}\text{ m}^3/\text{s} = 12.64 \times 10^{-6}\text{ m}^3/\text{s} \).