Venturimeter
It is a device used for measuring the rate of flow of liquid t pipes. Its working is based on Bernoulli’ s theorem.
Rate of flow of liquid,
where, a1 and a2 are area of cross-sections of tube at bra and narrower part and h is difference of liquid columns in ver tubes.
Torricelli’ s Theorem
Velocity of efflux( the velocity with which the liquid flows out orifice or narrow hole) is equal to the velocity acquired by a falling body through the same vertical distance equal to the dep orifice below the free surface of liquid.