ASVAB Automotive Information Practice Test 460306 Results

Your Results Global Average
Questions 5 5
Correct 0 2.70
Score 0% 54%

Review

1

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

49% Answer Correctly

radiator

water sleeve

water jacket

water pump


Solution

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


2

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

power

exhaust

intake

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.


3

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

53% Answer Correctly

speed sensor

vacuum booster

cylinder

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.


4

Too much fuel results in a __________ air-fuel mixture that burns quicker and cooler.

63% Answer Correctly

lean

light

rich

heavy


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.


5

Cylinder air and fuel intake valves, exhaust valves, and mounts for spark plugs and fuel injectors are contained in the:

45% Answer Correctly

piston ring

cylinder head

head gasket

manifold


Solution

Cylinders act as a guide for the pistons that translate the heat energy of combustion into the mechanical energy necessary to move a vehicle. Piston rings seal the piston to the cylinder to contain combustion gases and also regulate the oil distribution between the piston and cylinder wall. A cylinder head closes in the top of the cylinder forming the combustion chamber which is sealed by a head gasket (head). The head provides space for air and fuel intake valves, exhaust valves, and mounts for spark plugs and fuel injectors.