What is meant by critical velocity of a liquid?

Critical velocity of the liquid

What do you mean by critical velocity of a liquid?Derive an expression for it on the basis of dimensional considerations.

What do you mean by critical velocity?

What is critical velocity ?

What is meant by (i) particle velocity and (ii) wave velocity. How are they related ?

Define critical velocity.

Assuming that the critical velocity of flow of a liquid through a narrow tube depends on the radius of the tube, density of the liquid and viscosity of the liquid, find an expression for critical velocity.