Question

State Pascal’s law of transmission of pressure.

Answer 1

Hint: Pascal's law is a principle in fluid mechanics given by Blaise Pascal that states that a pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. This law is also known as Pascal's principle or the principle of transmission of fluid-pressure

Complete step by step solution:
The law was established by French mathematician Blaise Pascal in 1653 and published in 1663. This law can also be defined as “Pascal’s law for transmission of fluid pressure states that the pressure exerted anywhere in a confined incompressible fluid is transmitted undiminished and equally in all directions throughout the fluid.”
To understand the concept in a better way let us take an example. Let us consider a circular vessel which has 4 openings along with 4 pistons. When one of the pistons is moved downwards, a pressure is exerted which equally gets distributed in all the directions. This causes the other 3 pistons to move equal distance in the downward direction.
The various applications of pascal’s law of transmission of pressure are:
(A) Hydraulic brakes- In automobiles, the hydraulic brakes also work on the same principle. When a little force is applied on the pedal with the foot, the master piston moves inside the master cylinder, and the pressure caused by it is transmitted through the brake oil for acting on a piston of the larger surface area. A large force then acts on the piston and is pushed down due to which the brake shoes against brake lining. As a result, a small force on the pedal produces an extremely retarding force on the wheel.
(B) Hydraulic lift: In a hydraulic lift, two pistons are separated by the space filled with a liquid. A piston of small cross-section A is used to exert a force F on the liquid. The pressure is transmitted from the liquid to the larger cylinder attached with a larger piston of area and this results in an upward force. Thus, the piston is capable of supporting a large force . Also, by changing the force at A, the platform can be moved up or down.

Note:
Apart from having application in hydraulic lift and hydraulic lift, Pascal’s law also has applications in hydraulic press, which is the great achievement of Pascal’s Law application, in modern planes it is used for brakes, landing and various purposes.