Question

A prandtl tube (Pitot-static tube with C = 1) is used to measure the velocity of water. The differential manometer reading is 10 mm of liquid column with a relative density of 10. Assuming g = 9.8$m/s^2$, the velocity of water (in m/s) is ________

• A. 1.328

Answer 1

The correct option is A 1.328
Given data:
C = 1
x = 10 mm of liquid = 0.01 m of liquid
S = 10
${\rho }_{mano}=10\times 1000=10000kg/m^3$
g = 9.8 $m/s^2$
$h=x[\frac{{\rho }_{mano}}{{\rho }_{water}}-1]=0.01[\frac{10000}{1000}-1]$
=0.09m of water

Velocity of water,

$V=C\sqrt{2gh}=1\sqrt{2\times 9.8\times 0.09}$

=1.328 m/s