ASVAB Comprehensive Study Guide Flashcards

Page 1 – Electronics Information

• Direct Current (DC) – Steady, un-reversing flow produced by batteries; used in flashlights, boom boxes, computers.
• Alternating Current (AC) – Reverses direction many times ⁄ sec; easily transmitted long distances, used in homes.
• Voltage (V) – “Electrical pressure” controlling flow; higher V ⇒ more likely to arc or leak.
• General pacing tip – ~30 s per ASVAB question.

Fundamental Definitions

• Electricity – Energy carried by moving charges (electrons).
• Electrons – Negatively charged particles orbiting atomic nucleus.
• Conductor – Allows easy electron flow (silver, copper, aluminum).
• Insulator – Resists flow (rubber, plastic, ceramic).
• Circuit – Closed loop from source → load → back.
• Load – Device using power (heater, light, motor).
• Electric Current (A) – Rate of electron flow.
• Electric Power (W) – Rate energy consumed by device.
• Voltage Drop – $\Delta V$ consumed across part of circuit.

Page 2 – More Electronics

• Resistance (Ω) – Opposition to current; every circuit needs some to avoid short-circuit heat.
• Amperes (A) – Unit of current.
• Ohms (Ω) – Unit of resistance.
• Watts (W) – Unit of power.
• Frequency (f) – Cycles ⁄ sec in AC.

Electricity ↔ Magnetism

• Current in conductor → magnetic field → basis of motors, generators, transformers.
• Electromagnet – Wire coil + iron core; field exists only with current.
• Transformer – Two electromagnets side-by-side; changes $V$ & $A$.
‣ Step-up: more secondary turns → higher $V_{out}$.
‣ Step-down: opposite.
• Motor – Converts electrical → kinetic; rotor (electromagnet) repelled↔attracted by stator poles.
• Generator – Opposite of motor; kinetic → electrical.

Circuit Types

• Series – Same current through all loads; total load voltage = supply voltage.

Page 3 – Series & Parallel Rules

• Series Rule – $A$ same everywhere.
• Parallel Rule – $V$ same across branches.
• Typical house wiring: 3-wire cable — Black (hot), White (neutral), Bare (ground).

Key Formulas

• Ohm’s Law: $A = \dfrac{V}{Ω}$ (or $V = AΩ$, $Ω = \dfrac{V}{A}$).
• Electrical Power: $W = V \times A$.
• Total Resistance
‣ Series: $R<em>{T}=R</em>1+R<em>2+\dots$. ‣ Parallel: $\dfrac{1}{R</em>T}=\dfrac{1}{R_1}+\dots$.

Practical Items

• Circuit Breaker Box – Divides building load; cuts excessive current.
• Semiconductor (Si) – Conductor or insulator depending on dopants.
• Transistor – Switch, regulator, amplifier using small control current.
• Diode – One-way valve for current.

Page 4 – Auto Information (Engine Basics)

• Otto Cycle (4-stroke) – Intake → Compression → Power → Exhaust.
• Internal vs. External combustion – Cars (Otto, Diesel) burn inside; steam engines burn outside.

Components

• Cylinder & Piston – Chamber where combustion occurs; piston rings seal.
• Cylinder Head – Closes top; bolted to block.
• Head Gasket – Seals head-block joint.
• General time tip – ~60 s per Auto Shop question.

Page 5 – Lubrication & Engine Details

• Viscosity (SAE) – Thickness: SAE 5 (thin) → SAE 90 (thick); normal oil SAE 30–40.
• Spark Plug – Generates ignition spark.
• Connecting Rod & Crankshaft – Convert linear to rotary motion.
• Valve Train – Controls intake/exhaust flow.
• Firing Order – Non-sequential for smoothness.

Lubrication Notes

• Oil must be changed; filter too.
• Burning oil = blue exhaust.
• Oil pressure light ⇒ stop immediately.

Cooling System Basics

• Only ≈30 % fuel energy propels car; rest is heat removed by coolant (water + antifreeze + rust inhibitor).

Page 6 – Cooling & Drive Train

• Water Jackets – Passages in block/head.
• Radiator – Tubes + fins; cooled by airflow & fan.
• Coolant Mix – 50/50 protects to −30 °F.
• Water Pump – Circulates coolant.

Drive Train Functions

1. Optimal engine RPM via gears.

2. Provide reverse.

3. Idle without motion.

4. Drive 2 or 4 wheels.

5. Allow cornering without slip.

Page 7 – Differential & Transmissions

• Differential Jobs

1. Allow axle speed difference.

2. Turn power 90° (RWD).

3. Torque multiplication (3–4 : 1).

Transmissions

• Manual – Gearshift + clutch (pedal up = engaged).
• Automatic – Self-shifting.

Ignition System (Conventional)

• Breaker points → Coil primary (12 V) → Magnetic collapse → 10 kV secondary → Distributor cap/rotor → plugs.

Page 8 – Electronic Ignition & Power

• Electronic Ignition – Coil-on-plug; computer-timed; more power & MPG, less pollution.
• Battery (12 V lead-acid) – Electrolyte = sulfuric acid; terminals corrode ⇒ open circuit.
• Starter Motor – DC motor engages flywheel.
• Alternator – Engine-driven AC generator; rectified to DC for charging.
• ECU – Sensors (air mass, RPM, throttle, O₂, coolant, manifold pressure, alternator V) control engine.

Page 9 – Fuel & Diagnostics

• Fuel Tank – Charcoal canister traps fumes.
• Carburetor (obsolete) – Venturi draws fuel; rich > waste/pollute, lean > hot/weak.
• Fuel Injector – Solenoid valve sprays fuel; problems: dirt, water, freeze, vapor lock (rare now).

Electrical Troubleshooting

• Check loose/corroded connections; diagnostic computer useful.

Page 10 – Exhaust & Suspension

• Exhaust Manifold → Muffler → Tailpipe; plus emission devices.
• Power Steering – Hydraulic assist.
• Suspension – Leaf vs. coil springs; shock absorbers damp; worn shocks = wandering.
• Bearings – Ball or roller reduce friction.

Pollution Controls

• CO, Hydrocarbons, VOCs – Harmful by-products.
• PCV – Burns crankcase vapors.
• Catalytic Converter – Platinum-group catalysts convert pollutants.

Page 11 – Brakes, Tires, Wheels

• Tire Inflation – Check cold; hot reading higher.

Drum Brakes

• Wheel cylinder pushes shoes against drum; self-adjuster; worn shoes damage drum.

Disc Brakes

• Rotor + stationary pads; better stopping; pads squeal when worn; rotors machined or replaced.

Wheels & Tires

• Steel wheels bolted; radial-ply tires 30–40 psi; nails sizes (d) later.

Brake Hydraulics

• Incompressible fluid transmits pedal force.

Page 12 – ABS & Shop Intro

• ABS – Sensors detect skid; pump/release pressure.

Measuring Tools Listed

• Inside/Outside/Vernier Calipers, Micrometer, Carpenter’s Square, Sliding Bevel, Level, Tape Measure.

Page 13 – Measuring Tool Definitions

• Inside Caliper – Internal size.
• Outside Caliper – External size.
• Vernier – Inside/outside/depth precise.
• Micrometer – More precise than vernier.
• Carpenter’s Square – Right angles.
• Sliding Bevel – Any angle transfer.
• Level – Shows level/plumb via bubble.
• Tape – Flexible ruler in in / cm.

Page 14 – Wood-Working Tools 1

• Circular Saw (7¼ in) – Fast rip/cross/plywood.
• Hand Saw types: Crosscut vs. Rip; back saw for miter.
• Keyhole/Jigsaw – Intricate curves; coping saw for moulding.
• Jack Plane – Removes thin shavings; general purpose.
• Wood Chisel – ¼–1½ in; struck by mallet.

Page 15 – Metal Working Tools

• Hacksaw – Replaceable fine teeth; cuts on forward stroke.
• Tin Snips – Shear sheet metal; straight/curved.
• Pipe Cutter – Wheel cuts copper pipe.
• Tap & Die – Cut/restore threads; die (external), tap (internal); match OD & pitch.

Page 16 – Drills & Bits

• Electric drills sized by chuck (¼, ⅜, ½, ¾ in); pilot holes in metal; use oil cooling.
• Countersink – Conical recess for screw heads.
• Hole Saw – Large diameter hollow cutter.
• Chuck Key / keyless chucks.
• Center Punch – Locates bit.
• Auger Bit – Wood only; brace-and-bit compatible.

Page 17 – Drilling Details

• Drill large holes with smaller shank bits; harder metals need power & lubrication.
• Countersink bit = recess.
• Hole saws economical for wood, not hard metal.

Page 17 (continued) – Pounding Tools

• Claw Hammer 16 oz (24 oz framing, waffle face).
• Ball-Peen up to 3 lb; metalwork.
• Sledge (32 in handle) – Heavy blows.
• Rubber Mallet – Non-marring; drives chisels (wood-handled).

Turning & Grabbing Tools

List: Adjustable, Combination, Deep Socket, Ratchet, Torque, Allen, Arc-joint, Locking, Needle-nose, Bar Clamp, Pipe Wrench, Screwdrivers.

Page 18 – Wrench Details

• Adjustable (“Crescent”) – Variable jaw.
• Combination – Box + open end same size.
• Sockets attach via ¼, ⅜, ½, ¾ in drives; deep sockets clear protruding threads.
• Ratchet – One-way action.
• Torque – Tighten to spec.
• Allen – Hex recess screws.
• Arc-Joint (“Channel-lock”) – Adjustable pliers; not for nuts.
• Locking (“Vise-grips”) – Clamp forcefully.
• Needle-nose – Small parts/electrical.
• Bar Clamp – Holds work/glue.
• Pipe Wrench – Grips pipe via teeth.
• Screwdrivers – Flat & Phillips; length protects hands.

Page 20 – Fasteners

• Machine Screws require nut/threaded hole; Hex & Carriage bolts common.
• Nails measured by “penny” (d): 4d = 1½ in, 16d = 3½ in.
• Wood/Sheet-metal screws cut own threads; diameters #6, #8, etc.

Nail Types

• Brad, Tack, Finishing, Common, Sinker, Spike, Ring-shank, Spiral.

Page 21 – Metal Joining & Mechanics Intro

• Welding – Melt base metals.
• Soldering/Brazing – Melt filler (solder or bronze) only.
• Solder: plumbing/electronics; clean, flux, heat, apply.
• Brazing: filler bronze.

Mechanical Comprehension Test

• 25 Qs, 20 min; deals with levers, pulleys, etc.

Definitions

• Work – Force × distance.
• Energy – Capacity to do work: kinetic, potential, chemical, electric, nuclear.
• Force – Push/pull with magnitude & direction.
• Friction – Resistive force between surfaces.
• Gravity – Attraction; causes acceleration.
• Compression/Tension – Push together / pull apart.

Mechanical Advantage (MA)

1. $MA=\dfrac{\text{Load}}{\text{Effort}}$

2. $MA=\dfrac{\text{Effort distance}}{\text{Load distance}}$

Page 23 & 24 – Levers & Simple Machines

• Lever Parts: Fulcrum, Effort, Load, arms.
• Class 1: Fulcrum middle (seesaw).
• Class 2: Load middle (wheelbarrow); MA>1.
• Class 3: Effort middle (human arm); MA<1 but speed/distance gain.

Pulleys

• MA=\text{# supporting strands} (only strands that move).

Gears & Sheaves

• $MA<em>{gear}=\dfrac{T</em>{driven}}{T<em>{driver}}=\dfrac{D</em>{driven}}{D_{driver}}$.
• Belts (sheaves) same ratio via diameters.

Inclined Plane & Wedge

• $MA=\dfrac{\text{horizontal length}}{\text{rise}}$.
• Wedge is moving incline; same formula.

Wheel & Axle

• $MA=\dfrac{R<em>{wheel}}{R</em>{axle}}$ (or reciprocal if axle drives wheel).

Compound Machines

• Total $MA$ = product of individual $MA$s.

Page 26 – Support & Fluids

• For off-center loads between supports, nearer support carries more.

Fluid Principles

• Liquids incompressible: flow rate same everywhere.
• Bernoulli: Speed ↑ ⇒ Pressure ↓.
• Water pressure = weight / area.
Example: 1600 lb over $2\,ft\times4\,ft=8\,ft^2$ ⇒ $200\,lb/ft^2$.
• Gas laws: Compress ⇒ warms + potential energy; expand ⇒ cools.

Page 28 – Tank Filling Problem Method

1. Convert units (gal/sec → gal/min).

2. Net flow = in − out.

3. Multiply by time.
   Example solved: 300 gal added in 5 min.

Page 28–32 – Arithmetic Reasoning Basics

Includes:
• Place value (periods, decimal part).
• Addition / Subtraction with integers (number-line method).
• Subtract by adding opposite.
• Multiplication / Division sign rules.
• Order of Operations (PEMDAS).
• Rounding rules (5 rounds up).
• Factors, primes, composites, prime factorization list up to 20.

Page 32–35 – Fractions

• Proper, improper, mixed numbers; convert.
• Equivalent fractions by × ⁄ ÷ same number.
• LCD via multiples or prime factors.
• Add/subtract like/unlike; reduce.
• Multiply: multiply numerators & denominators, reduce.
• Divide: multiply by reciprocal.
• Mixed numbers: convert → improper then operate; “word problem” examples (board length & checkout time).

Page 37 – Decimals & Percent

• Decimal point separates ones; place values tenths → thousandths.
• Convert percent ↔ decimal: move point two places.
• 10 % quick: shift decimal left once.
• Find % of number via decimal × number.

Page 39–40 – Exponents, Scientific Notation, Roots

• $a^1=a$; $a^0=1$ ($a\neq0$); same-base multiplication: add exponents.
• Scientific notation: $N=a\times10^k$ with 1\le a<10.
• Square roots inverse of square; perfect squares 1–100 list.
• Manual root via iterative average.

Page 41–44 – Statistics & Word Problems

• Mean average; Median center; Mode most frequent.
• Translate words to algebra: key addition, subtraction, multiplication, division phrases.
• Strategy: read, list info & units, define unknowns, draw, note key words, beware “per”, “less than”, “ratio/difference of”.

Page 51–55 – Algebra Essentials

• Expression – combo of variables (letters), coefficients, constants.
• Variables stand for unknown numbers.
• Real numbers: rational vs. irrational (π example).

Solving Linear Equations

• Treat equation like balance; use inverse operations; keep sides equal.
• Examples for addition, subtraction, multiplication, division.

Inequalities

• Solve like equations; if × ⁄ ÷ by negative, reverse symbol.
• Graph on number line (open vs. closed dots).

Ratios & Proportions

• Ratios written $\dfrac{a}{b},\ a:b,\ a\text{ to }b$.
• Equal ratios produce proportions; solve via cross-products.

Systems of Equations

• Substitution Method steps.
• Elimination Method: align coefficients, add/subtract to cancel variable.

Monomials Operations

• Add/subtract like terms.
• Multiply: add exponents, multiply coefficients.
• Divide: subtract exponents, divide coefficients.

Page 60–61 – Geometry Formulas

Areas

• Triangle $A=\tfrac12 bh$
• Rectangle $A=lw$
• Parallelogram $A=bh$
• Trapezoid $A=\tfrac12(b<em>1+b</em>2)h$
• Circle $A=\pi r^2 ,\ C=2\pi r$

Volumes / Surface Areas

• Rectangular Prism $V=lwh$; $SA=2(lw+lh+wh)$.
• General Prism $V=Bh$; $SA=\sum \text{faces}$.
• Cylinder $V=Bh$; $SA=2B+Ch$.
• Square Pyramid, Cone, Sphere formulas listed (see figure list).

Coordinate Geometry

• Slope-intercept $y=mx+b$.
• Point-slope $y-y<em>1=m(x-x</em>1)$.
• Distance = rate × time $d=rt$.

Polygon Interior Angles

• Sum $=180(n-2)$.
• Regular polygon single angle $=\dfrac{180(n-2)}{n}$.

Simple Interest

$I=prt$.

Special Right Triangles

• 45-45-90: sides $x,x,x\sqrt2$.
• 30-60-90: sides $x,x\sqrt3,2x$.

Page 44–48 – Word Knowledge & Roots

• Common roots: agri, anthropo, astro, bio, cardio, cede, chromo, demos, derma, dyna, geo, helio, hydro, hypno, ject, magni, manu, mono, ortho, pod, psycho, pyro, script, terra, thermo, zoo.
• Prefixes: ante-, anti-, auto-, bene-, circum-, contra-, de-, dis-, ecto-, endo-, ex-, equi-, extra-, hyper-, hypo-, in-, inter-, intra-, intro-, macro-, mal-, micro-, multi-, neo-, non-, pan-, poly-, post-, pre-, pro-, proto-, pseudo-, re-, retro-, semi-, sub-, super-, tele-, trans-, uni-.
• Number prefixes: mono, di/bi, tri, tetra/quad, quint/pent, hex, sept/hept, oct, nov, dec, centi, milli.
• Negative prefixes: a-, de-, dis-, in-, non-, un-, contra-.
• Time/location prefixes: pre-, post-, ante-, inter-, infra-, trans-, sub-, circum-, ultra-.

Paragraph Comprehension Tips

A. Detail – fact check.
B. Main-idea title.
C. Context/meaning of word.
D. Inference – unstated conclusion.
Reading strategy: quick read, closer look, heed keywords, ignore opinions, manage time.

End of Notes