ASVAB Automotive Information Practice Test 129564 Results

Your Results Global Average
Questions 5 5
Correct 0 2.78
Score 0% 56%

Review

1

Gases from combustion are pushed out through the exhaust valve as the piston travels up the cylinder to top dead center. This describes which engine stroke?

67% Answer Correctly

intake

power

exhaust

compression


Solution

During the exhaust stroke, just before the piston reaches bottom dead center the exhaust valve opens. The resulting gases from combustion are then pushed out through the exhaust valve as the piston travels up the cylinder to top dead center, completing stroke four of the four-stroke piston cycle.


2

Ignition timing is measured in number of degrees:

59% Answer Correctly

after bottom dead center

after top dead center

before bottom 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

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

54% Answer Correctly

speed sensor

cylinder

brake line

vacuum booster


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.


4

Which of the following enables heat transfer from the cylinder heads to the coolant?

49% Answer Correctly

water pump

water sleeve

water jacket

radiator


Solution

A water jacket is a coolant-filled casing that allows heat transfer from the engine block and cylinder heads to the liquid coolant.


5

Which of the following is not a common vehicle cylinder arrangement?

49% Answer Correctly

opposed

V-type

vertical

inline


Solution

Cylinder number and arrangement depends on the purpose of the engine. Smaller (four and six cylinder) engines in front-wheel drive vehicles often use an inline design which orients cylinders vertically over the crankshaft and aligns them in a row. Other common orientations are a horizontal/opposed design which places cylinders flat facing each other with the crankshaft between them and a V-type design common in six and eight cylinder engines that features one cylinder head per block of cylinders oriented at a 60 to 90 degree angle to each other with the crankshaft at the bottom of the V.