Question

According to Bernoullis equation $\frac{P}{\rho g}+h+\frac{1}{2}\frac{{{v}^{2}}}{g}=\text{constant}$ The terms A, B and C are generally called respectively:

• A. gravitational head, pressure head and velocity head
• B. gravity, gravitational head and velocity head
• C. pressure head, gravitational head and velocity head
• D. gravity, pressure and velocity head

Answer 1

Answer: (C)

pressure head, gravitational head and velocity head

Answer 2

According to Bernoullis theorem, in case of steady flow of incompressible and non-viscous liquid through a tube of non-uniform cross-section, the sum of the pressure, the potential energy per unit volume and the kinetic energy per unit volume is same at every point in the tube, i.e.,
$P+\rho gh+\frac{1}{2}\rho {{v}^{2}}=\text{constant}$
Dividing this expression by
$\rho g,$ we have $\frac{P}{\rho g}+\frac{{{v}^{2}}}{2g}+h=\text{constant}$
In this expression $\frac{P}{\rho g}$
is called the pressure head, $\frac{{{v}^{2}}}{2g}$
the velocity head and $h$ the gravitational head.