ASVAB Automotive Information Practice Test 813228 Results

Your Results Global Average
Questions 5 5
Correct 0 3.18
Score 0% 64%

Review

1

What is the pimary advantage of using power brakes on a vehicle?

62% Answer Correctly

allows the use of antilock brakes

requires less brake fluid to operate the braking system

provides higher hydraulic pressure in the braking system

utilizes battery power to assist in braking


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.


2

Engine oil viscosity is rated using the format XW-XX with the number preceding the W indicating viscosity at __________ ℉ and the XX indicating viscosity at __________ ℃.

66% Answer Correctly

0, 100

0, 0

100, 100

100, 0


Solution

The primary component of the lubrication system is engine oil. Engines require oil blends with different thickness (viscosity) and additives depending on their operating conditions. Viscosity is rated using the format XW-XX with the number preceding the W (winter) rating the oil’s viscosity at 0 ℉ (-17.8 ℃) and the XX indicating viscosity at 100 ℃.


3

The spark plugs fire a few extra degrees before top dead center when the engine is running faster. In this case the engine's timing is:

62% Answer Correctly

advanced

synchronous

asynchronous

retarded


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.


4

Ignition timing is measured in number of degrees:

59% Answer Correctly

after top dead center

before bottom dead center

after 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.


5

The piston moves downward in the cylinder creating a vacuum that pulls an air-fuel mix into the combustion chamber. This describes which engine stroke?

68% Answer Correctly

intake

exhaust

power

compression


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.