What does Pascal's Law in hydraulics state?

Pascal's Law, also known as Pascal's principle, asserts that when pressure is applied to a confined fluid, that pressure change is transmitted equally in all directions throughout the fluid. This principle is foundational in hydraulics, as it explains how hydraulic systems operate, allowing for the force applied in one location to influence the entire fluid system uniformly.

This means that if you were to apply pressure at one point in a closed hydraulic system, every other point within that system would experience the same increase in pressure, regardless of the fluid's position or container shape. This property allows for efficient transfer of force, which is the underlying principle in hydraulic machinery like lifts and brakes.

The other options have inaccuracies regarding the nature of pressure transmission in fluids. For instance, stating that pressure change occurs only in specific areas does not reflect the uniform behavior outlined by Pascal's Law, while a reference to pressure below atmospheric levels being non-existent does not align with the principle, as low pressures can exist and are relevant in various applications. Thus, the statement that pressure applied to a confined fluid is transmitted equally throughout captures the essence of Pascal's Law accurately.