Question

The correct formula of critical velocity $\left(V_c\right)$ is________

Answer 1

Critical velocity:

1. Critical velocity may be defined as the speed at which the flow of a liquid through a tube changes from laminar to turbulent.
2. The critical velocity depends on the coefficient of viscosity, the density of the liquid, and the radius of the tube.
3. Mathematically,

$V_c=\frac{R_e\eta }{\rho r}$, where $R_e$=Reynolds number, $\eta$=coefficient of viscosity, $\rho$=density of the fluid, $r$=radius of the tube.