how does the reduced compressibility in liquids used in hydraulics?

Answer 1

The operation of a hydraulic press depends on the incompressibility of the liquid that fills it. If the fluid were compressible, its pressure and volume could change, and the movement of one piston would not necessarily result in movement of the other. However, due to the absence of significant compressibility, the parts move as expected in order to maintain a constant pressure.

Answer 2

This reduced compressibility or incompressibility of liquids is very important in Hydraulics because it means, volume of liquids won't change even with applied pressure. In a hydraulic system, this involves a confined fluid (of course incompressible) with two pistons, a smaller one where the input force is applied and a larger one of which a much larger force is produced. When force is applied on the smaller piston (smaller cross-sectional area), the pressure exterted is transmitted in all directions undiminished so when the liquid is pushed to the bigger piston, the Force is multiplied.

Analyze this:

For example the larger area is 3x the area of the smaller piston, then

Pressure in small piston = pressure in large piston
But Pressure = Force/A
so Force (small) = Pressure x A
Force (large) = Pressure x 3 A

so if you exert 10 Newton for on a small piston, the larger piston will be able to produce 30 N. Meaning your force was multiplied three times