ASVAB Automotive Information Practice Test 451525 Results

Your Results Global Average
Questions 5 5
Correct 0 3.17
Score 0% 63%

Review

1

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

84% Answer Correctly

battery

solenoid

alternator

camshaft


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

Coolant is circulated through the engine by the:

61% Answer Correctly

water jacket

water pump

radiator

camshaft


Solution

The water pump is driven by a belt connected to the crankshaft and ensures that coolant moves through the engine and radiator.


3

The radiator is responsible for tranferring heat from the coolant to:

60% Answer Correctly

outside air

engine block

thermostat

cylinder heads


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

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

synchronous

retarded

advanced

asynchronous


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 an advantage that disc brakes have over drum brakes?

50% Answer Correctly

provide a larger contact area

provide more braking force

use less brake fluid

are more easily cooled


Solution

Brakes utlize friction to slow vehicle tires. Drum brakes employ a cast iron drum that roates with the vehicle axle. When hydraulic pressure is applied to the brake assemblies at the wheels, internal pistons expand and push brake shoes outward into contact with the brake drum slowing the rotation of the axle. More powerful disc brakes operate by pinching a rotating disc betweeen two brake pads and allow for a larger surface area to contact the disc, provide more force, and are more easily cooled.