Question

In the vacuum suspended system, the brakes are applied when
A. Atmospheric pressure is applied to one side of the diaphragm.
B. Vacuum is applied to both sides of the diaphragm.
C. Atmospheric pressure is applied to both sides of the diaphragm.
D. Vacuum is applied to one side of the diaphragm.

Answer 1

Hint: In-order to answer this type of question based on hydraulic brakes and hydraulic jacks, we have to understand Pascal's Law and its applications. We will have to understand the basic working of brakes and how it relates to Pascal’s law. Note that here we do not use fluid, instead we will use vacuum.

Complete answer:
Pascal ‘s Law: Pressure applied on a fluid travels uniformly and equally in all the directions.Now in the vacuum suspended brake booster this concept is used, simply replacing the fluid with vacuum.

Now, in a vacuum suspended system, there is vacuum on both the sides of the diaphragm, thus when-ever the brake is applied, vacuum is released on one side of the booster and thus the difference in air pressure pushes down the diaphragm for the braking action. Hence from the above understanding, it is very clear that in the vacuum suspended system, the brakes are applied when atmospheric pressure is applied to one side of the diaphragm.

Thus, the correct option is option A.

Note: A vacuum booster consists of a round enclosed housing and a diaphragm. The power brake vacuum uses the engine vacuum to apply the hydraulic braking system. These vacuum boosters are of two types:
-An atmospheric suspended brake booster
-A vacuum suspended brake booster.