Pascal's Law NEET MCQ - NEET Practice Questions with Answers

  Pascal's law states that if the gravity effect is neglected then the pressure at a point in a fluid at rest is the same in all directions.

This law helps us to understand the isotropic nature of pressure.

            Pascal's law can be also stated as 

The increase in pressure at one point of the enclosed liquid in the equilibrium of rest is transmitted equally to all other points of the liquid and also to the walls of the container, provided the effect of gravity is neglected.

The applications of this law can be seen in Hydraulic lifts, hydraulic presses, hydraulic brakes, etc

Working of hydraulic lift-

A hydraulic lift is used to lift the heavy loads.

For the above figure 

If a small force f is applied on the piston of C then the pressure exerted on the liquid

$P=\frac{f}{a}$

Where 

a = Area of a cross-section of the piston in C

This pressure is transmitted equally to the piston of cylinder D.

$$\frac{f}{\text{ So }}=\frac{F}{A}\Rightarrow F=\frac{f}{a}A$$

Where $\mathrm{F}=$ Upward force acting on the piston of cylinder D.
A=Area of a cross-section of the piston in $D$
Condition of Hydraulic Lift-
$A\gg$ a therefore

$$F\gg f$$
 

So heavy load placed on the larger Piston is easily lifted upward.