Q.A hydraulic lift is designed to lift heavy objects of maximum mass 2000 kg. The area of cross section of piston carrying the load is 2.25×10⁻² m². What is the maximum pressure the piston would have to bear? (A) 0.8711×10⁶ N/m²
(B) 0.5862×10⁷ N/m²
(C) 0.4869×10⁵ N/m²
(D) 0.3271×10⁴ N/m²

Pascal's law states that the pressure applied at any point of an enclosed fluid at rest is transmitted equally and undiminished to every other point of the fluid, and to the walls of its container, provided the effect of gravity is neglected — demonstrated experimentally with a multi-armed vessel of frictionless pistons of different areas, where the pressure works out identical at every piston regardless of its individual area.

This principle underlies two major practical machines. A hydraulic lift applies a small force $F_1$ on a small piston of area $A_1$, generating a pressure that is transmitted undiminished to a much larger piston of area $A_2$, producing there a much larger output force $F_2 = F_1(A_2/A_1)$ — enough to lift a heavy load using only a modest input force. Hydraulic brakes work identically: pressing a brake pedal pushes a small master-cylinder piston forward, and the resulting pressure is transmitted through incompressible brake fluid to a much larger slave-cylinder piston at each wheel, converting a light pedal force into a large braking force pressed against the wheel's brake disc. In both machines the area ratio $A_2/A_1$ is the whole source of the force multiplication — the same enclosed fluid simply carries the applied pressure, unchanged, from the small piston to the large one.