- Pascal’s principle states that in a confined fluid, an externally applied pressure is transmitted uniformly in all directions.
- Pascal’s principle is also known as the principle of transmission of pressure in a liquid.
Q & A
Q: Suggest an experiment to prove Pascal’s Principle.
- When the plunger is pushed in, the water squirts equally from all the holes.
- This shows that the pressure applied to the plunger has been transmitted uniformly throughout the water.
- A hydraulic system applies Pascal’s principle in its working mechanism. It can be used as a force multiplier.
- In this hydraulic system, a small force, Fl is applied to the small piston X results in a large force, F2 at the large piston Y. The pressure, due to the force, F1, is transmitted by the liquid to the large piston.
- According to Pascal’s principle,
F1A1 = F2A2
Change of Oil Level in a Hydraulic System
In the diagram to the left, when piston-X is pressed down, piston-Y will be push up. The change of the piston levels of the 2 pistons is given by the following equation:
h1A1 = h2A2