A water tank kept on the ground has an orifice of 2mm diameter on the vertical side. What is the minimum height of the water above the orifice for which the output flow of water is found to be turbulent? ( Assume, `g=10m//s^(2), rho_("water")=10^(3)kg//m^(3)`, viscosity `=1` centi-poise )

Options

A. 3 cm
B. 4 cm
C. 5 cm
D. 2 cm

Explanation

`(**)` Here, `D=2mm, eta=1` centi-poise`=10^(-3)`Pa-s
and density of the water, `rho=10^(3)kg//m^(3)`
For flow to be just turbulent, `R_(e)=3000`
`:." "v=(R_(e) eta)/(rho D)=(3000xx10^(-3))/(10^(3)xx2xx10^(-3))=1.5`
We know that the velocity head, `h=(v^(2))/(2g)`
`rArr h=((1.5)^(2))/(2xx10)=0.1125~=11cm`
So, no option is matched.