ASVAB Automotive Information Practice Test 636041 Results

Your Results Global Average
Questions 5 5
Correct 0 2.92
Score 0% 58%

Review

1

What is the name of the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air?

62% Answer Correctly

residual ratio

ignition ratio

stoichiometric ratio

combustion ratio


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.


2

Which of the following is a common firing order for four-cylinder engines?

66% Answer Correctly

1-3-4-2

4-3-2-1

3-1-2-4

1-2-3-4


Solution

The stroke cycle of an engine is governed by the crankshaft which serves to regulate the firing order of the cylinders. All cylinders are not on the same stroke at the same time and correct firing order is important to balance engine operation and minimize vibrations. A common firing order for four-cylinder engines is 1-3-4-2 which indicates that cylinders 1 and 3 fire (power stroke)together and cylinders 4 and 2 fire together.


3

Which of the following maintains pressure in the cooling system?

61% Answer Correctly

radiator cap

water jacket

water pump

thermostat


Solution

The radiator is responsible for tranferring heat from the coolant to the outside air. Radiator hoses transfer coolant to and from the engine to the radiator and a radiator cap maintains pressure in the cooling system to increase the boiling point of the coolant mixture and thus allow it to absorb more heat.


4

Which of the following statements about an inline cylinder configuration is false?

54% Answer Correctly

works well in eight cylinder engines

increases the length of the engine

cylinders can be completely vertical or slanted

cylinders are configured in a single row


Solution

An inline cylinder configuration places the cylinders in a single row either completely vertical or slanted. Due to this arrangement, an inline cylinder configuration makes the engine longer and, although it works well in four cylinder engines, performace suffers in larger engines due to the difficulty in evenly distributing the air-fuel mixture over the length of the engine.


5

A __________ is a drive axle that extends from a transaxle or differential to one of the drive wheels.

50% Answer Correctly

steering linkage

drive shaft

half shaft

control arm


Solution

A half shaft is a drive axle that extends from a transaxle or differential to one of the drive wheels. There are two half shafts per drive axle, one for each wheel, each doing "half" the job.