Mechanical Engineering - Automobile Engineering - Discussion

Answer is D.

We generally applying the brakes using leg efforts, here hydraulic pump supplies pressurized fluid which boosts the braking forces.

When the river pushes the brake pedal then the brake pedal transfers some force to the poppet valve which tends to push atmospheric air into the vacuum chamber and increases the brake force. Because atmospheric pressure is high and we know that pressure always has its path towards low pressure. So that the reason the pressure difference will give additional effort to apply brakes.

The answer is correct for Petrol engine case. But, Diesel engines do not produce such vacuum in intake manifold, hence a vacuum pump driven by a battery is used to create a vacuum inside the brake booster.

Vacuum pump is only in diesel cars. Because there is no throttle to make vacuum.

Option C is right for petrol cars.

@Shaik Baji.

Then, which one is the right answer?

Most of the the cars will take the vacuum pump which is fitted on Alternator.

C is wrong, how intake air can be transferred to brake booster.