What is Pascal’s Law?

According to Pascal’s Law,

“The external static pressure applied on a confined liquid is distributed or transmitted evenly throughout the liquid in all directions”.

The static pressure acts at right angles to any surface in contact with the fluid. Pascal also found that the pressure at a point for a static fluid would be the same across all planes passing through that point in that fluid. Pascal’s law is also known as Pascal’s principle or principle of transmission of fluid-pressure. In 1653, Pascal law was stated by French mathematician Blaise Pascal.

Pressure is equal to the force divided by the area on which it acts. According to Pascal’s principle, in a hydraulic system a pressure exerted on a piston produces an equal increase in pressure on another piston in the system. If the second piston has an area 10 times that of the first, the force on the second piston is 10 times greater, though the pressure is the same as that on the first piston. This effect is exemplified by the hydraulic press, based on Pascal’s principle, which is used in such applications as hydraulic brakes.

Pascal Law Formula :-

Following is the formula of Pascal law:

$$F = PA$$ Where F is the force applied, P is the pressure transmitted, and A is the cross-sectional area.

Applications of Pascal’s Law :-

• Hydraulic Lift: The image you saw at the beginning of this article is a simple line diagram of a hydraulic lift. This is the principle of the working of hydraulic lift. It works based on the principle of equal pressure transmission throughout a fluid (Pascal’s Law).

• The construction is such that a narrow cylinder (in this case A) is connected to a wider cylinder (in this case B). They are fitted with airtight pistons on either end. The inside of the cylinders is filled with fluid that cannot be compressed.

• Pressure applied at piston A is transmitted equally to piston B without diminishing the use of the fluid that cannot be compressed. Thus, piston B effectively serves as a platform to lift heavy objects like big machines or vehicles. A few more applications include a hydraulic jack and hydraulic press, and forced amplification is used in the braking system of most cars.