ASVAB Automotive Information Practice Test 237833

Questions 5
Topics Air-Fuel Mixture, Battery, Engine Block, Fluid Reservoir, Power Stroke

Study Guide

Air-Fuel Mixture

The stoichiometric ratio defines the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air. For gasoline fuel, the stoichiometric ratio is about 14.7:1 or for every one gram of fuel, 14.7 grams of air are required. Too much air results in a lean air-fuel mixture that burns more slowly and hotter while too much fuel results in a rich mixture that burns quicker and cooler.

Battery

The battery supplies the power necessary to start the engine when the ignition switch is is turned on.

Engine Block

The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.

Fluid Reservoir

The fluid reservoir stores the brake fluid that the master cylinder uses to maintain hydraulic pressure.

Power Stroke

During the power stroke, just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. The resulting expansion due to combustion pushes the piston back down the cylinder toward bottom dead center.