A siphon has a uniform circular cross-section of diameter  $8/\sqrt{\pi } cm$ with its crest A, 1.8 m above  the water level in vessel B of large cross-section (g = 10 m/$s^2$, density of water is  $1000kg/m^3$ and atmospheric pressure $P_0={10}^5$ N/ $m^2$) 
 

Applying Bernoulli’s equation at C and D, we have              

$$\begin{gathered} P_0+0+\rho g\left(3.6\right)=P_0+\frac{1}{2}\rho v^2+0 \\ {\Rightarrow }_{ }v=6{\sqrt{2}}_{ }m/s \end{gathered}$$

Volume blown per unit time   
$=av=\pi r^{2}v=96\sqrt{2}\times {10}^{-4}{m}^3/s$                          
 Similarly, at A and C,        
$$\begin{gathered} P_A+\frac{1}{2}\rho v^2+\rho g(3.6+1.8)=P_0+\frac{1}{2}\rho vH2+0 \\ {\Rightarrow }_{ }{P}_A=0.46\times {10}^{5}N/m^2 \end{gathered}$$