ASVAB Automotive Information Practice Test 137074

Questions 5
Topics Alternator, Control Arms, Master Cylinder, Power Brakes, Steering Linkage

Study Guide

Alternator

Once the engine is running, the alternator provides electrical current to recharge the battery and power the electrical system. The alternator is driven by the engine's crankshaft and produces alternating current (AC) which is then fed through a rectifier bridge to convert it to the direct current (DC) required by the electrical system. A voltage regulator controls the output of the alternator to maintain a consistent voltage (approx. 14.5 volts) in the electrical system regardless of load.

Control Arms

Control arms (upper and lower) connect a vehicle's suspension to the frame. The connection to the wheels is through ball joints which allow the control arms to turn and move up and down simultaneously. The frame connection uses bushings.

Master Cylinder

The master (brake) cylinder converts pressure on the brake pedal to hydraulic pressure in the brake lines.

Power Brakes

Power brakes multiply the force a driver applies to the brake pedal using a vacuum booster connected to the engine intake manifold. This provides for much higher hydraulic pressure in the braking system than could be generated by the driver alone. Antilock brakes (ABS) use speed sensors and adjust the brake pressure at each wheel to prevent skidding and allow the driver more steering control in slippery conditions.

Steering Linkage

The steering linkage is a system of pivots and connecting parts between the steering gear and the control arms. The steering linkage transfers the motion of the steering gear output shaft to the steering arms that turn the wheels.