ASVAB Automotive Information Practice Test 179781 Results

Your Results Global Average
Questions 5 5
Correct 0 3.23
Score 0% 65%

Review

1

Which of the following is not a function of antifreeze?

54% Answer Correctly

lubricates the cooling system

raises the boiling point of water

keeps water from freezing at low temperatures

aids heat transfer


Solution

Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.


2

Ignition timing is measured in number of degrees:

59% Answer Correctly

before bottom dead center

after bottom dead center

after top dead center

before top dead center


Solution

Ignition timing defines the point in time at the end of the compression stroke that the spark plug fires. Measured in number of degrees before top dead center (BTDC), the exact point that the spark plugs initiate combustion varies depending on the speed of the engine. The timing is advanced (the spark plugs fire a few more degrees BTDC) when the engine is running faster and retarded when it's running slower.


3

In a four-stroke piston cycle, one piston is always:

84% Answer Correctly

compressing the air-fuel mixture

all of these are correct

exhausting gases

delivering power


Solution

In a four-stroke cycle engine there is always one piston delivering power, one exhausting gases, one drawing in the air-fuel mixture, and one compressing that mixture.


4

The intake ports on the cylinder heads is fed outside air via the:

66% Answer Correctly

intake pressure regulator

intake manifold

intake air pump

intake control module


Solution

The intake manifold distributes outside air to the intake ports on the cylinder heads. The intake air filter removes any airborne contaminants before the air enters the engine.


5

Which engine stroke starts with the piston at top dead center?

61% Answer Correctly

exhaust stroke

power stroke

intake stroke

compression stroke


Solution

The four-stroke piston cycle of internal combustion engines starts with the piston at top of the cylinder head (top dead center or TDC) during the intake stroke. The piston moves downward in the cylinder creating a vacuum that pulls an air-fuel mix into the combustion chamber through the now open intake valve.