Hydraulic brakes are based on
A. Pascal’s law
B. Torricelli’s law
C. Newton’s law
D. Boyle’s law

Hint: To get the solution, first understand what hydraulic brake is and then understand the different laws that are listed in the option. Once both the details are understood properly, it will be easy to compare and get the answer for this question. The law’s listed are used for different purposes, so until you understand it, getting the final answer is tough.

Complete solution:
A hydraulic brake is an arrangement of braking mechanism which internally uses brake fluid, typically containing glycol ethers or diethylene glycol, to transfer and apply pressure from the main controlling mechanism to the braking mechanism.
Hydraulic brakes work on the principle of Pascal’s law. According to this law whenever some pressure is applied on fluid it travels uniformly in all the directions. Therefore, when we apply force on a small piston, the pressure will get created which is transmitted through the fluid to a larger piston. As a result of this larger amount of force, uniform braking is applied on all four wheels of the system. As braking force is generated due to hydraulic pressure on the brakes, they are known as hydraulic brakes. Liquids are used instead of gas, as liquids are incompressible, even under high pressure.

Therefore, the correct answer is Option (A).

Note:
This question is just based on concept. If the concept is clear, then getting the correct answer is easy. The law’s listed in the option are used in different situations and have different use cases, if you can understand the practical use case of this law then getting the final answer is easy.