\({P_0} + \frac{1}{2}\rho v_1^2\rho gh = {P_0} + \frac{1}{2}\rho v_2^2 + 0\)
\({v_2} = \sqrt {v_1^2 + 2gh} = \sqrt {0.16 + 2 \times 10 \times 0.2} = 2.03m/s\)
From equation of continuity
\({A_2}{v_2} = {A_1}{v_1}\)
\(\pi \frac{{D_2^2}}{4} \times {v_2} = \pi \frac{{D_1^2}}{4}{v_1}\)
\( \Rightarrow {D_1} = {D_2}\sqrt {\frac{{{v_1}}}{{{v_2}}}} = 3.55 \times {10^{ - 3}}m\)
[પાણીની ઘનતા $f_{{w}}=1000 \;{kg} {m}^{-3}$ અને હવાની ઘનતા $f_{{a}}=1.2 \;{kg} {m}^{-3}, {g}=10 \;{m} / {s}^{2}$ હવાનો શ્યાનતાગુણાંક $=18 \times 10^{-5}\; {Nsm}^{-2}$ ]
$( g =9.8\,m / s ^2$ આપેલું છે.)