Example $6$

A $30cm15cm$ venturimeter is provided in a vertical pipeline carrying oil of specific gravity $0\mathrm{.}9,$ the flow being upwards. The difference in elevation of the throat section and entrance section of the venturimeter is $30$ cm $.$ The differential U$-$tube mercury manometer shows a gauge deflection of $25$ cm $.$ Calculate :

$($i$)$ the discharge of oil, and

$($ii$)$ the pressure difference between the entrance section and the throat section.

Take the coefficient of discharge as $0\mathrm{.}98$ and specific gravity of mercury as $13\mathrm{.}6.$

$h=y(\frac{S_m}{S_L}-1)$

$h=(\frac{p_1}{}+z_1)-(\frac{p_2}{}+z_2)$

TTT

H$.$W