Q.

A small hole of area of cross-section 2 mm2 is present near the bottom of a fully filled open tank of height 2 m. Taking g=10 m/s2, the rate of flow of water through the open hole would be nearly              [2019]
 

1 6.4×10-6 m3/s  
2 12.6×10-6 m3/s  
3 8.9×10-6 m3/s  
4 2.23×10-6 m3/s  

Ans.

(2)

According to Torricelli's theorem,

Velocity, v=2gh=2×10×2=6.32 m/s.

From equation of continuity, 

Volume of liquid flowing per second, Q=Av

=2×10-6×6.32=12.6×10-6 m3/s