Braking Systems Questions and Answers

Answer: C

Comparing the speeds of the four wheels reveals a wheel decelerating far faster than the others, which indicates impending lock. Deceleration sensors are used on some four wheel drive systems as an addition. Wheel speed is the fundamental input. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb.

Answer: D

The modulator isolates the wheel, dumps pressure to an accumulator, then pumps it back, cycling many times a second. The pulsing felt at the pedal is the pump returning fluid. Each wheel is controlled independently on a four channel system. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. A symptom that appears under one condition and not another is what narrows the diagnosis quickly. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision.

Answer: A

A rolling tyre generates lateral force and a locked one does not, so the driver can steer around an obstacle while braking hard. On gravel or fresh snow the system actually lengthens the stop, which is why the first claim is qualified. Most errors here come from carrying across a result from a neighbouring case where it does not hold. The order in which the effects act is what decides the outcome, so it is worth establishing first. The quantity that varies and the quantity that does not are worth naming before any substitution is attempted.

Answer: B

A locked wheel builds a wedge of loose material ahead of it that helps to stop the vehicle, and anti-lock prevents that wedge forming. The trade is accepted because steering control is worth more. Some systems detect the surface and adapt. Naming what changes and what stays the same is the reliable route through questions of this shape. Checking which component actually carries the load settles most questions of this kind at once. A single measurement chosen to respond to the one asymmetry beats several that respond to shared behaviour.

Answer: C

Traction control brakes a spinning wheel and often reduces engine torque as well, using the same sensors and modulator. Electronic brake force distribution and brake assist also use the hardware but for different purposes. The shared hardware is the point. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. Tracing the requirement back to the physical constraint that produces it makes the answer follow.

Answer: D

Stability control compares the driver's steering input with the actual yaw rate and brakes an individual wheel to generate a correcting moment. It needs a yaw sensor and a steering angle sensor beyond the anti-lock hardware. It is mandatory on new vehicles. A symptom that appears under one condition and not another is what narrows the diagnosis quickly. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision.

Answer: A

The system must know what the driver intends and what the vehicle is doing, which needs steering angle for the first and yaw rate with lateral acceleration for the second. Cameras belong to driver assistance rather than to stability control. The order in which the effects act is what decides the outcome, so it is worth establishing first. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. Most errors here come from carrying a result across from a neighbouring case where it does not hold.

Answer: B

Weight transfers forward under braking so the rear wheels lock first unless their pressure is limited, which the proportioning valve does above a threshold. Residual pressure valves exist for drum brakes but serve a different purpose entirely. Checking which component actually carries the load settles most questions of this kind at once. Most errors here come from carrying across a result from a neighbouring case where it does not hold. The shared properties explain why these belong to one family, and the differences explain why more than one exists.

Answer: C

Electronic distribution meters rear pressure through the anti-lock valves and adapts to the actual load continuously. Load sensing valves were the mechanical predecessor and are still found on commercial vehicles. The electronic version needs no extra hardware. Tracing the requirement back to the physical constraint that produces it makes the answer follow. Naming what changes and what stays the same is the reliable route through questions of this shape.

Answer: D

Above a certain temperature the binder in the friction material decomposes and gives off gas, which reduces the coefficient of friction sharply. Contamination and water reduce friction too but are not fade. Recovery follows once the brake cools. The shared behaviour explains why these belong together and the differences explain why both exist. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. The shared properties explain why these belong to one family, and the differences explain why more than one exists.