ASVAB FULL-LENGTH PRACTICE EXAM
130 Questions | Complete Answer Key & Rationales | High-Yield Review
TABLE OF CONTENTS
Section Subject Area Questions
I General Science (GS) 1–20
II Arithmetic Reasoning (AR) 21–40
III Word Knowledge (WK) 41–55
IV Paragraph Comprehension (PC) 56–65
V Mathematics Knowledge (MK) 66–85
VI Electronics Information (EI) 86–95
VII Auto & Shop Information (AS) 96–105
VIII Mechanical Comprehension (MC) 106–120
IX Assembling Objects (AO) 121–130
SECTION I: GENERAL SCIENCE (GS)
Questions 1–20
1. In which layer of the atmosphere does all weather affecting Earth take place?
A) Stratosphere
B) Mesosphere
C) Troposphere
D) Thermosphere
🔴 Correct Answer: C
Rationale: The troposphere is the lowest layer of Earth's atmosphere and contains approximately 80% of the atmosphere's
mass. All weather phenomena—including cloud formation, precipitation, storms, and wind—occur within this layer due to
the presence of water vapor and vertical air currents.
,2. What is the chemical symbol for sodium?
A) So
B) Na
C) S
D) N
🔴 Correct Answer: B
Rationale: Sodium's chemical symbol is Na, derived from its Latin name natrium. This is a commonly tested fact on the
ASVAB General Science section.
3. Which of the following is a non-renewable resource?
A) Sunlight
B) Wind
C) Copper
D) Timber
🔴 Correct Answer: C
Rationale: Copper is a metallic mineral resource that exists in finite quantities and cannot be replenished on a human
timescale. Sunlight, wind, and timber are renewable resources that can be naturally replenished.
4. The tympanic membranes are also known as the:
A) Ear canals
B) Eustachian tubes
C) Ear drums
D) Cochleae
🔴 Correct Answer: C
Rationale: The tympanic membrane is the anatomical term for the eardrum. It is a thin, cone-shaped membrane that
separates the external ear from the middle ear and vibrates in response to sound waves.
5. When sodium atoms form sodium ions, they:
A) Gain electrons
B) Lose electrons
C) Share electrons
D) Become neutral
🔴 Correct Answer: B
Rationale: Sodium (Na) has one valence electron in its outermost shell. To achieve a stable electron configuration, sodium
loses this electron to form a Na⁺ ion with a +1 charge. This is a fundamental concept in ionic bonding.
6. What are the two main gases that make up stars?
,A) Oxygen and nitrogen
B) Hydrogen and helium
C) Carbon and oxygen
D) Nitrogen and hydrogen
🔴 Correct Answer: B
Rationale: Stars are primarily composed of hydrogen (about 73%) and helium (about 25%) by mass. Nuclear fusion in stellar
cores converts hydrogen into helium, releasing tremendous energy in the process.
7. The process by which energy is provided at the cellular level is called:
A) Respiration
B) Metabolism
C) Photosynthesis
D) Digestion
🔴 Correct Answer: B
Rationale: Metabolism encompasses all chemical reactions that occur within cells, including those that release energy
(catabolism) and those that consume energy (anabolism). Cellular respiration is one metabolic process, but metabolism is
the broader term.
8. In chemistry, to be classified as an organic substance, a compound must contain:
A) Oxygen
B) Nitrogen
C) Carbon
D) Hydrogen
🔴 Correct Answer: C
Rationale: Organic chemistry is defined as the study of carbon-containing compounds. While many organic compounds
also contain hydrogen, oxygen, or nitrogen, the presence of carbon atoms is the defining characteristic of organic
substances.
9. A net force of 15 N is applied to an object initially at rest. The object reaches a velocity of 12 m/s in 4 seconds. What is
the mass of the object?
A) 3 kg
B) 5 kg
C) 12 kg
D) 15 kg
🔴 Correct Answer: B
Rationale: Using Newton's second law, F = ma. First calculate acceleration: a = Δv/t = (12 m/s - 0)/4 s = 3 m/s². Then m =
F/a = 15 N/3 m/s² = 5 kg.
10. Which of the following actions produces a chemical change?
, A) Mixing salt and sugar
B) Drying wet clothes
C) Boiling water
D) Burning wood
🔴 Correct Answer: D
Rationale: Burning wood is a chemical change because the molecules in the wood are converted into new molecules
(carbon dioxide, water vapor, ash) that are chemically different from the original. The other options are physical changes
where the chemical composition remains unchanged.
11. The gravitational interaction of Earth and the Moon is responsible for:
A) Earth's rotation
B) The tides
C) Earth's seasons
D) The phases of the Moon
🔴 Correct Answer: B
Rationale: The gravitational pull of the Moon, and to a lesser extent the Sun, causes ocean tides. As Earth rotates, different
areas pass through these tidal bulges, creating high and low tides.
12. What is the function of the epiglottis?
A) Filtering air
B) Producing sound
C) Preventing choking
D) Regulating breathing rate
🔴 Correct Answer: C
Rationale: The epiglottis is a flap of cartilage located at the base of the tongue. During swallowing, it covers the opening to
the larynx (voice box) to prevent food and liquid from entering the airway, thereby preventing choking.
13. Small rocks shed by asteroids and comets that reach Earth are called:
A) Meteoroids
B) Meteorites
C) Meteors
D) Asteroids
🔴 Correct Answer: B
Rationale: A meteoroid becomes a meteor when it enters Earth's atmosphere (producing a "shooting star"). If it survives
atmospheric entry and reaches the ground, it is called a meteorite.
14. Which of the following does NOT contain oxygenated blood?
130 Questions | Complete Answer Key & Rationales | High-Yield Review
TABLE OF CONTENTS
Section Subject Area Questions
I General Science (GS) 1–20
II Arithmetic Reasoning (AR) 21–40
III Word Knowledge (WK) 41–55
IV Paragraph Comprehension (PC) 56–65
V Mathematics Knowledge (MK) 66–85
VI Electronics Information (EI) 86–95
VII Auto & Shop Information (AS) 96–105
VIII Mechanical Comprehension (MC) 106–120
IX Assembling Objects (AO) 121–130
SECTION I: GENERAL SCIENCE (GS)
Questions 1–20
1. In which layer of the atmosphere does all weather affecting Earth take place?
A) Stratosphere
B) Mesosphere
C) Troposphere
D) Thermosphere
🔴 Correct Answer: C
Rationale: The troposphere is the lowest layer of Earth's atmosphere and contains approximately 80% of the atmosphere's
mass. All weather phenomena—including cloud formation, precipitation, storms, and wind—occur within this layer due to
the presence of water vapor and vertical air currents.
,2. What is the chemical symbol for sodium?
A) So
B) Na
C) S
D) N
🔴 Correct Answer: B
Rationale: Sodium's chemical symbol is Na, derived from its Latin name natrium. This is a commonly tested fact on the
ASVAB General Science section.
3. Which of the following is a non-renewable resource?
A) Sunlight
B) Wind
C) Copper
D) Timber
🔴 Correct Answer: C
Rationale: Copper is a metallic mineral resource that exists in finite quantities and cannot be replenished on a human
timescale. Sunlight, wind, and timber are renewable resources that can be naturally replenished.
4. The tympanic membranes are also known as the:
A) Ear canals
B) Eustachian tubes
C) Ear drums
D) Cochleae
🔴 Correct Answer: C
Rationale: The tympanic membrane is the anatomical term for the eardrum. It is a thin, cone-shaped membrane that
separates the external ear from the middle ear and vibrates in response to sound waves.
5. When sodium atoms form sodium ions, they:
A) Gain electrons
B) Lose electrons
C) Share electrons
D) Become neutral
🔴 Correct Answer: B
Rationale: Sodium (Na) has one valence electron in its outermost shell. To achieve a stable electron configuration, sodium
loses this electron to form a Na⁺ ion with a +1 charge. This is a fundamental concept in ionic bonding.
6. What are the two main gases that make up stars?
,A) Oxygen and nitrogen
B) Hydrogen and helium
C) Carbon and oxygen
D) Nitrogen and hydrogen
🔴 Correct Answer: B
Rationale: Stars are primarily composed of hydrogen (about 73%) and helium (about 25%) by mass. Nuclear fusion in stellar
cores converts hydrogen into helium, releasing tremendous energy in the process.
7. The process by which energy is provided at the cellular level is called:
A) Respiration
B) Metabolism
C) Photosynthesis
D) Digestion
🔴 Correct Answer: B
Rationale: Metabolism encompasses all chemical reactions that occur within cells, including those that release energy
(catabolism) and those that consume energy (anabolism). Cellular respiration is one metabolic process, but metabolism is
the broader term.
8. In chemistry, to be classified as an organic substance, a compound must contain:
A) Oxygen
B) Nitrogen
C) Carbon
D) Hydrogen
🔴 Correct Answer: C
Rationale: Organic chemistry is defined as the study of carbon-containing compounds. While many organic compounds
also contain hydrogen, oxygen, or nitrogen, the presence of carbon atoms is the defining characteristic of organic
substances.
9. A net force of 15 N is applied to an object initially at rest. The object reaches a velocity of 12 m/s in 4 seconds. What is
the mass of the object?
A) 3 kg
B) 5 kg
C) 12 kg
D) 15 kg
🔴 Correct Answer: B
Rationale: Using Newton's second law, F = ma. First calculate acceleration: a = Δv/t = (12 m/s - 0)/4 s = 3 m/s². Then m =
F/a = 15 N/3 m/s² = 5 kg.
10. Which of the following actions produces a chemical change?
, A) Mixing salt and sugar
B) Drying wet clothes
C) Boiling water
D) Burning wood
🔴 Correct Answer: D
Rationale: Burning wood is a chemical change because the molecules in the wood are converted into new molecules
(carbon dioxide, water vapor, ash) that are chemically different from the original. The other options are physical changes
where the chemical composition remains unchanged.
11. The gravitational interaction of Earth and the Moon is responsible for:
A) Earth's rotation
B) The tides
C) Earth's seasons
D) The phases of the Moon
🔴 Correct Answer: B
Rationale: The gravitational pull of the Moon, and to a lesser extent the Sun, causes ocean tides. As Earth rotates, different
areas pass through these tidal bulges, creating high and low tides.
12. What is the function of the epiglottis?
A) Filtering air
B) Producing sound
C) Preventing choking
D) Regulating breathing rate
🔴 Correct Answer: C
Rationale: The epiglottis is a flap of cartilage located at the base of the tongue. During swallowing, it covers the opening to
the larynx (voice box) to prevent food and liquid from entering the airway, thereby preventing choking.
13. Small rocks shed by asteroids and comets that reach Earth are called:
A) Meteoroids
B) Meteorites
C) Meteors
D) Asteroids
🔴 Correct Answer: B
Rationale: A meteoroid becomes a meteor when it enters Earth's atmosphere (producing a "shooting star"). If it survives
atmospheric entry and reaches the ground, it is called a meteorite.
14. Which of the following does NOT contain oxygenated blood?
