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Free ASVAB practice test

26 questions from the app's free trial, across every subtest

Answer each question, then open Show answer to see the right choice and why it is right. The real computer-based ASVAB has 135 questions like these across 10 subtests, each on its own clock.

Question 1 · General Science

Which part of a cell releases most of the energy the cell uses?

  1. AThe mitochondria
  2. BThe nucleus
  3. CThe cell membrane
  4. DThe ribosomes
Show answer

A. The mitochondria

Mitochondria carry out cellular respiration, breaking down glucose with oxygen to release energy as ATP. The nucleus stores DNA, the membrane controls what enters and leaves, and ribosomes build proteins.

Question 2 · General Science

Which particle in an atom carries a negative charge?

  1. AThe electron
  2. BThe proton
  3. CThe neutron
  4. DThe nucleus as a whole
Show answer

A. The electron

Electrons are negative and orbit the nucleus. Protons are positive, neutrons are neutral, and together protons and neutrons make the nucleus positive overall.

Question 3 · General Science

Which vitamin does the human body make when skin is exposed to sunlight?

  1. AVitamin D
  2. BVitamin C
  3. CVitamin A
  4. DVitamin B12
Show answer

A. Vitamin D

Sunlight on skin converts a cholesterol compound into vitamin D, which helps the body absorb calcium for strong bones. Vitamin C comes from fruits and vegetables, A from sources like carrots and liver, and B12 from animal products.

Question 4 · Arithmetic Reasoning

At the exchange you buy items costing $3.45, $2.80 and $6.25. You pay with a $20 bill. How much change should you get?

  1. A$7.50
  2. B$8.50
  3. C$6.50
  4. D$7.25
Show answer

A. $7.50

Add the purchases first: 3.45 + 2.80 + 6.25 = 12.50. Then subtract from the payment: 20.00 − 12.50 = 7.50. Lining up decimal points when adding prevents the most common slip.

Question 5 · Arithmetic Reasoning

A truck's 48-gallon fuel tank is three-quarters full. How many gallons are in the tank?

  1. A36
  2. B32
  3. C40
  4. D12
Show answer

A. 36

Three-quarters of 48 is (3 ÷ 4) × 48 = 36 gallons. 'Of' with a fraction means multiply. The tank has 12 gallons of space left, which is the trap answer.

Question 6 · Arithmetic Reasoning

Jake is twice as old as Sam, and their ages add up to 36. How old is Jake?

  1. A24
  2. B18
  3. C12
  4. D27
Show answer

A. 24

Let Sam be x, so Jake is 2x. Then x + 2x = 36, so 3x = 36 and x = 12. Jake is 2 × 12 = 24. Answering Sam's age (12) is the common trap.

Question 7 · Word Knowledge

Abate most nearly means:

  1. ALessen
  2. BIncrease
  3. CBegin
  4. DScatter
Show answer

A. Lessen

To abate is to become less intense or widespread: a storm abates, pain abates, noise abates. Think of 'a-BATE' as beating something down to a lower level.

Question 8 · Word Knowledge

The sentry remained vigilant through the night, scanning the perimeter for any movement. Vigilant most nearly means:

  1. AWatchful
  2. BExhausted
  3. CHidden
  4. DArmed
Show answer

A. Watchful

Vigilant means keeping careful watch for danger. The sentence's clue is 'scanning the perimeter.' The root is Latin 'vigil,' to stay awake, as in a vigil.

Question 9 · Word Knowledge

The prefix 'pre-' in words like preliminary and preflight means:

  1. ABefore
  2. BAfter
  3. CAgainst
  4. DTogether
Show answer

A. Before

'Pre-' means before: a preflight check happens before flight, a preliminary round comes before the main event. Knowing common prefixes unlocks unfamiliar words.

Question 10 · Paragraph Comprehension

Dehydration degrades performance long before a person feels thirsty. By the time thirst registers, the body may already be down a quart of fluid, and judgment, coordination and endurance all suffer. For this reason, experienced instructors enforce scheduled drinking rather than waiting for recruits to ask for water. What is the main point of the passage?

  1. ADrinking should happen on a schedule because thirst lags behind the body's needs
  2. BRecruits complain about water discipline
  3. CA quart of fluid is the most a person can safely lose
  4. DInstructors dislike unscheduled breaks
Show answer

A. Drinking should happen on a schedule because thirst lags behind the body's needs

Every sentence supports one idea: thirst is a late signal, so drinking must be scheduled. The other options twist details or invent claims the passage never makes.

Question 11 · Paragraph Comprehension

Automated beacons have replaced keepers at every working lighthouse in the country, and most of the towers themselves now serve as museums. Yet something is lost when no one climbs the stairs each evening. The keeper was a promise that someone was watching the water, and no sensor, however reliable, makes a promise. The author's purpose is mainly to:

  1. AExpress regret about what automation replaced
  2. BExplain how automated beacons work
  3. CArgue that lighthouses should be demolished
  4. DGive a history of lighthouse construction
Show answer

A. Express regret about what automation replaced

Phrases like 'something is lost' and the closing line about promises signal lament, not instruction or technical explanation. Purpose questions ask why the author wrote, not what happened.

Question 12 · Paragraph Comprehension

In a study of marksmanship, soldiers who slept less than five hours scored twenty percent worse than their rested counterparts, and their scores kept falling with each additional night of short sleep. Coffee improved alertness for an hour or two but did nothing for accuracy. The passage suggests that:

  1. ACaffeine cannot substitute for sleep where precision matters
  2. BFive hours of sleep is enough for most soldiers
  3. CMarksmanship depends mostly on natural talent
  4. DCoffee worsens shooting accuracy
Show answer

A. Caffeine cannot substitute for sleep where precision matters

Coffee helped alertness but 'did nothing for accuracy,' while sleep loss kept hurting scores — so caffeine is no substitute. The passage never says coffee made shooting worse, only that it didn't help.

Question 13 · Mathematics Knowledge

Solve for x: 2x + 7 = 19

  1. Ax = 6
  2. Bx = 13
  3. Cx = 5
  4. Dx = 12
Show answer

A. x = 6

Subtract 7 from both sides: 2x = 12. Divide by 2: x = 6. Check: 2(6) + 7 = 19. Undo addition before multiplication when isolating x.

Question 14 · Mathematics Knowledge

What is the mean of 3, 7, 8 and 10?

  1. A7
  2. B8
  3. C7.5
  4. D6
Show answer

A. 7

Add the values: 3 + 7 + 8 + 10 = 28. Divide by the count: 28 ÷ 4 = 7. The mean is the arithmetic average.

Question 15 · Mathematics Knowledge

A right triangle has one angle of 35°. What is the third angle?

  1. A55°
  2. B65°
  3. C45°
  4. D35°
Show answer

A. 55°

Triangle angles sum to 180°. With the right angle: 180 − 90 − 35 = 55°. In any right triangle the two acute angles are complementary — they sum to 90°.

Question 16 · Electronics Information

A 12-volt battery is connected across a 4-ohm resistor. How much current flows?

  1. A3 amperes
  2. B48 amperes
  3. C0.33 ampere
  4. D8 amperes
Show answer

A. 3 amperes

Ohm's law: I = V ÷ R = 12 ÷ 4 = 3 amperes. The triangle V = I × R rearranges to solve for any of the three quantities.

Question 17 · Electronics Information

A 4-ohm and a 6-ohm resistor are connected in series. What is the total resistance?

  1. A10 ohms
  2. B2.4 ohms
  3. C24 ohms
  4. D5 ohms
Show answer

A. 10 ohms

In series, resistances simply add: 4 + 6 = 10 ohms. Current must pass through both, so each adds opposition. The 2.4-ohm figure would be the parallel combination.

Question 18 · Electronics Information

In standard U.S. household wiring, the ground wire is usually:

  1. AGreen or bare copper
  2. BBlack
  3. CWhite
  4. DRed
Show answer

A. Green or bare copper

Ground wires are green or bare copper. Black (and sometimes red) wires are hot, carrying power; white is the neutral return. Mixing these up is dangerous.

Question 19 · Auto Information

What is the correct order of the four strokes in a gasoline engine?

  1. AIntake, compression, power, exhaust
  2. BIntake, power, compression, exhaust
  3. CCompression, intake, exhaust, power
  4. DPower, intake, compression, exhaust
Show answer

A. Intake, compression, power, exhaust

The piston draws in the air-fuel mix (intake), squeezes it (compression), the spark fires it to push the piston down (power), and the burned gases are pushed out (exhaust). Remember 'suck, squeeze, bang, blow.'

Question 20 · Auto Information

The main purpose of engine oil is to:

  1. AReduce friction between moving parts
  2. BCool the radiator
  3. CImprove fuel combustion
  4. DClean the exhaust gases
Show answer

A. Reduce friction between moving parts

Oil forms a thin film between metal parts so they slide instead of grind. It also carries away heat and holds contaminants until the filter traps them. Running low on oil destroys an engine fast.

Question 21 · Auto Information

In a turn, the outside wheels travel farther than the inside wheels. Which component allows the driven wheels to rotate at different speeds?

  1. AThe differential
  2. BThe clutch
  3. CThe camshaft
  4. DThe master cylinder
Show answer

A. The differential

The differential splits engine torque between the two driven wheels while letting them spin at different speeds. Without it, tires would scrub and hop in every turn.

Question 22 · Shop Information

A hacksaw is designed to cut:

  1. AMetal
  2. BPlywood sheets
  3. CDrywall
  4. DCeramic tile
Show answer

A. Metal

A hacksaw's fine-toothed, replaceable blade is made for metal pipe, rod and bolts. Wood saws have larger teeth; tile is cut with abrasive or scoring tools.

Question 23 · Shop Information

Soldering joins metal parts by:

  1. AMelting a softer filler metal that bonds the parts without melting them
  2. BMelting the edges of both parts together
  3. CCompressing the parts under high pressure
  4. DGluing with a metallic epoxy
Show answer

A. Melting a softer filler metal that bonds the parts without melting them

In soldering (and brazing), only the filler melts and flows into the joint; the base metals stay solid. Welding is different: it fuses the base metals themselves.

Question 24 · Shop Information

Plywood is strong for its weight because it is made of:

  1. AThin wood layers glued with the grain alternating direction
  2. BSawdust pressed with resin
  3. CA single thick board sanded smooth
  4. DPlastic-coated hardboard
Show answer

A. Thin wood layers glued with the grain alternating direction

Each veneer layer's grain runs perpendicular to its neighbors, so the sheet resists bending and splitting in every direction. Sawdust pressed with resin describes particleboard, a weaker material.

Question 25 · Mechanical Comprehension

A wheelbarrow is which class of lever?

  1. ASecond class — the load sits between the wheel (fulcrum) and your hands (effort)
  2. BFirst class — the fulcrum sits between load and effort
  3. CThird class — the effort sits between fulcrum and load
  4. DIt is not a lever
Show answer

A. Second class — the load sits between the wheel (fulcrum) and your hands (effort)

Fulcrum at the wheel, load in the tray, effort at the handles: fulcrum-load-effort is a second-class lever, which always multiplies force. A seesaw is first class; tweezers are third class.

Question 26 · Mechanical Comprehension

Sliding friction between a crate and the floor depends mainly on:

  1. AThe weight pressing the surfaces together and their roughness
  2. BThe crate's color and temperature
  3. CThe crate's speed only
  4. DThe surface area of contact only
Show answer

A. The weight pressing the surfaces together and their roughness

Friction is the normal force times the friction coefficient of the two surfaces. Surprisingly, contact area barely matters: a crate on its side slides about as hard as on its end.

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