ASVAB Automotive Information Practice Test 876780 Results

Your Results Global Average
Questions 5 5
Correct 0 3.05
Score 0% 61%

Review

1

When a car engine is running, what provides electrical current to recharge the battery and power the electrical system?

84% Answer Correctly

camshaft

alternator

solenoid

battery


Solution

Once the engine is running, the alternator provides electrical current to recharge the battery and power the electrical system. The alternator is driven by the engine's crankshaft and produces alternating current (AC) which is then fed through a rectifier bridge to convert it to the direct current (DC) required by the electrical system. A voltage regulator controls the output of the alternator to maintain a consistent voltage (approx. 14.5 volts) in the electrical system regardless of load.


2

__________ results from oil buildup in the combustion chamber.

43% Answer Correctly

preignition

engine knock

combustion

detonation


Solution

Preignition results from the buildup of fuel deposits and/or oil in the combustion chamber. These deposits increase chamber pressure and reduce heat tranfer to the coolant. The trapped heat then raises the temperature of the air-fuel mix to the point that it combusts before ignition.


3

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

49% Answer Correctly

water sleeve

water pump

radiator

water jacket


Solution

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


4

The air-fuel mixture is delivered to the combustion chamber by a(n):

76% Answer Correctly

intake valve

exhaust valve

fuel valve

air valve


Solution

The combustion chamber is located in the cylinder head and contains the combustion of the air-fuel mixture. This mixture is delivered by an intake valve and the waste gases from combustion are removed from the combustion chamber by the exhaust valve.


5

Which of the following is the result of combustion being initiated by a source other than the spark plug?

51% Answer Correctly

detonation

pre-ignition

ignition

pre-combustion


Solution

Normal combustion in an engine is initiated by a spark plug and results in the complete burning of the air-fuel mixture. If combustion is initiated by a source other than the spark plug, by a hot spot in the cylinder or combustion chamber for example, pre-ignition results. Detonation results if the air-fuel mixture explodes instead of burning. Detonation can cause extremes in pressure in the combustion chamber leading to engine damage.