Give two uses of Pascal's law.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ When you squeeze one end of a tube to get toothpaste out from the other end,Pascal's principle is observed.
Reason $R:$ $A$ change in the pressure applied to an enclosed incompressible fluid is transmitted undiminished to every portion of the fluid and to the walls of its container.
In the light of the above statements,choose the most appropriate answer from the options given below:

The area of cross-section of the wider tube shown in the figure is $800\,cm^2$. If a mass of $12\,kg$ is placed on the massless piston,the difference in the heights $h$ in the level of water in the two tubes is ........ $m$.

$A$ piston of cross-section area $100 \, cm^2$ is used in a hydraulic press to exert a force of $10^7 \, dynes$ on the water. The cross-sectional area of the other piston which supports an object having a mass $2000 \, kg$ is:

$A$ hydraulic automobile lift is designed to lift cars with a maximum mass of $3000 \; kg$. The area of cross-section of the piston carrying the load is $425 \; cm^{2}$. What maximum pressure would the smaller piston have to bear?

Increase in pressure at one point of the enclosed liquid in equilibrium of rest is transmitted equally to all other points of liquid. This is as per ...........