Final answer:
The device that adjusts brake cylinder pressure in proportion to car loading is called a load sensing valve or proportioning valve. It operates based on Pascal's principle, ensuring the pressure created by the master cylinder when the brake pedal is pressed is proportionally transmitted to the wheel cylinders, regardless of the vehicle's load.
Step-by-step explanation:
The device which helps to automatically adjust the brake cylinder pressure so that it is in proportion to the car loading is the load sensing valve or proportioning valve. Hydraulic brakes operate on the basis of Pascal's principle, which states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid, such that the pressure variations remain the same. The force a driver exerts on the brake pedal is increased by a simple lever and again by the hydraulic system, and it is distributed equally to all the brake cylinders in the system.
When you apply a force of 100 N to the brake pedal, this force is applied to the master cylinder through a lever. The consequent pressure is then equally distributed to the slave cylinders in the wheels. For systems designed to handle different loading conditions, such as power brakes, these may include a motorized pump that does most of the work to create the necessary pressure in the system.