Pascal's Law states that pressure in a confined fluid is equal and acts____.

• A. On each surface
• B. Perpendicular to all surfaces
• C. Only at the bottom of the vessel
• D. Only against the external load

Answer: (B)

In a static, confined fluid, pressure is the same in all directions at a point and the force due to that pressure acts normal to any surface in contact with the fluid. This means the pressure on a wall or on any submerged surface pushes perpendicular to that surface, not along it. So the best way to fill the blank is that pressure acts perpendicular to all surfaces. The other descriptions don’t capture this universal, direction-normal action of fluid pressure.