ASVAB Automotive Information Practice Test 115806 Results

Your Results Global Average
Questions 5 5
Correct 0 3.02
Score 0% 60%

Review

1

What is the name of the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air?

62% Answer Correctly

stoichiometric ratio

ignition ratio

residual ratio

combustion ratio


Solution

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.


2

What function does a two-stroke cycle engine perform on the second stroke?

51% Answer Correctly

combustion and exhaust

fuel intake and exhaust

fuel intake and compression

compression and combustion


Solution

The two strokes of a two-stroke cycle engine are fuel intake and compression then combustion and exhaust.


3

Just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. This describes which engine stroke?

61% Answer Correctly

intake

power

exhaust

compression


Solution

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.


4

What links each piston to the engine's crankshaft?

72% Answer Correctly

halfshaft

connecting rod

cylinder arm

piston ring


Solution

A connecting rod employs a wrist pin to link each piston to the engine's crankshaft.


5

Power brakes multiply the force a driver applies to the brake pedal using a __________ connected to the engine intake manifold.

53% Answer Correctly

vacuum booster

cylinder

speed sensor

brake line


Solution

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.