Pascal law: If gravity effect is neglected the pressure at every point of liquid in equilibrium of rest is same.
Hydraulic lift It is used to lift the heavy loads. Its working is based on Pascal’s law. A simple hydraulic lift is shown in Figure. Here C and D are two cylinders of different areas of cross section. They are connected to each other with a pipe E. Each cylinder is provided with airtight frictionless piston. Let a, and A be the areas of cross-sections of the pistons in C and D respectively, where a < < A. The cylinders are filled with an incompressible liquid.
Let a downward force f be applied on the piston of C. Then the pressure exerted on the liquid, of C. Then the pressure exerted on the liquid, P = F/a.
According to Pascal’s law, this pressure is transmitted equally to piston of cylinder D will be
F’ = PA = \(\frac{F}{a}\)A = F\(\frac{A}{a}\).
