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20 multiple-choice questions and 9 flashcards on Auto Information, about 7% of the ASVAB bank. Every one carries a written rationale.
Auto Information is one of 11 chapters in CoStudy's ASVAB bank, and it holds 20 of the bank's 300 multiple-choice questions — roughly 7% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.
Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.
5 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.
The alternator's main job is to:
Answer: B — Recharge the battery and power electrical systems while the engine runs
A) That's the starter. B) Alternator generates current from engine rotation. C) Cooling system. D) Intake/injection.
When the clutch pedal is pressed in a manual transmission, the engine is:
Answer: B — Disconnected from the wheels
A) Clutch doesn't start engine. B) Correct — clutch disengages the engine from drivetrain so gears can be shifted without grinding. C) RPM may briefly free-rev but that's not the purpose. D) Unrelated.
During which stroke are both valves closed and the spark plug fires near the top of the piston travel?
Answer: B — The end of compression, just before the power stroke begins
B) Correct — ignition occurs with both valves sealed as the piston nears top dead center on compression, starting the power stroke. A) tempts because the intake valve is central to combustion, yet an open valve cannot hold compression. C) tempts because the exhaust valve opens after burning, not during ignition. D) tempts because overlap is a real event, but both valves open is the opposite of sealed.
List the four-stroke cycle in order:
Answer: A — Intake, compression, power, exhaust
A) Correct order. B/C/D) Out of sequence.
In a disc brake assembly, the component that squeezes the pads against the rotor is which of the following?
Answer: D — The caliper, which clamps the pads onto the rotor
D) Correct — hydraulic pressure moves caliper pistons that clamp the pads to both faces of the rotor. A) tempts because it is the matching part in a drum brake, applied to the wrong system. B) tempts because the master cylinder does create pressure, but it sits at the pedal. C) tempts as a brake part, but drums belong to the other brake type.
4 cards from the 9 in this chapter.
What is the purpose of the differential?
It splits drive torque to the two drive wheels while allowing them to rotate at different speeds in a turn, preventing tire scrub and driveline binding.
What does the clutch do in a manual transmission, and what replaces it in an automatic?
The clutch disconnects engine power from the transmission so gears can be changed. • An automatic uses a torque converter, a fluid coupling that also multiplies torque at low speed.
A vehicle's tires show wear on both outer edges only. What is the most likely cause?
Chronic underinflation, which lets the tread shoulders carry the load. • Center-only wear indicates overinflation, and one-edge wear suggests a camber or alignment problem.
Purpose of a clutch in a manual transmission?
Disengages engine from drivetrain so the driver can shift gears.
These are a sample. The full Auto Information chapter runs 29 items with per-chapter progress tracking, on the web and in the iOS app.