ASVAB Automotive Information Practice Test 451253 Results

Your Results Global Average
Questions 5 5
Correct 0 3.16
Score 0% 63%

Review

1

Exhaust gases from cylinder exhaust valves are collected by the:

65% Answer Correctly

muffler

exhaust manifolds

tail pipe

catalytic converter


Solution

The cast iron exhaust manifolds collect engine exhaust gas from multiple cylinder exhaust valves and deliver it to the exhaust pipe. Exhaust manifolds can be generic or specially tuned (header pipes) to the engine. Header pipes deliver higher performance but are more expensive and less durable.


2

What combines the suspension spring and shock absorber into one unit?

73% Answer Correctly

wheel cylinder

strut

wheel hub

knuckle


Solution

Because a compressed spring will ex­tend violently, shock absorbers must be used to dampen the spring’s compression and extension cycles. Struts combine the spring and shock into one unit


3

Which of the following regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston?

66% Answer Correctly

halfshaft

crankshaft

connecting arm

camshaft


Solution

The camshaft is linked to the crankshaft through a timing belt and regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston. An engine designated OverHead Camshaft (OHC) locates the camshaft in the cylinder head. An engine with Double OverHead Camshaft (DOHC) has two camshafts, one to regulate the intake valves and one to regulate the exhaust valves.


4

Ignition timing is measured in number of degrees:

59% Answer Correctly

before top dead center

after top dead center

before bottom dead center

after bottom 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

Which of the following is not a function of antifreeze?

54% Answer Correctly

aids heat transfer

raises the boiling point of water

lubricates the cooling system

keeps water from freezing at low temperatures


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.