How the Electronics Information subtest works
Electronics Information is the sixth subtest. On the CAT-ASVAB you have 10 minutes for 15 scored questions, 40 seconds each. Some are facts: what a component does, what a unit measures, what a symbol stands for. Others are short calculations, such as the current through a resistor in a circuit diagram.
The official topic list is electrical tools, symbols, devices and materials; electrical circuits; electrical and electronic systems; and electrical currents.
Like every subtest it adapts to your answers and does not let you go back. It is not part of the AFQT, but it is in the Air Force Electronic composite, the Navy Electronics and Marine Corps Electrical composites, and the Army Electronics, General Maintenance and Mechanical Maintenance line scores, so it matters most for technical jobs.
How to approach Electronics Information
Sort each question in a few seconds, then use the matching tool:
- Fact or calculation? Facts you either know or can narrow down. Calculations need a formula.
- For calculations, write Ohm’s law, voltage = current × resistance (V = I × R), and power, P = V × I, then rearrange for what is asked.
- For a circuit, decide first whether resistors are in series (one path; resistances add) or in parallel (several paths; the total is smaller than the smallest resistor).
- Check the units: volts for voltage, amperes for current, ohms for resistance and watts for power.
Worked example
“Two resistors, 6 ohms and 3 ohms, are connected in parallel across a 12-volt battery. What is the total current drawn from the battery?” A. 1.33 amperes, B. 4 amperes, C. 6 amperes, D. 36 amperes.
The resistors are in parallel, so their combined resistance is product over sum: (6 × 3) ÷ (6 + 3) = 18 ÷ 9 = 2 ohms. By Ohm’s law, current = voltage ÷ resistance = 12 ÷ 2 = 6 amperes, option C.
Option A treats the resistors as if they were in series (9 ohms), and option B uses only the 3-ohm resistor. A quick check: in parallel each resistor gets the full 12 volts, so the currents are 2 and 4 amperes, which add up to 6.
Tips for the real Electronics Information subtest
- Learn the circuit symbols for a battery, resistor, switch, capacitor, diode, lamp and ground. US diagrams usually draw a resistor as a zigzag line.
- Know what the common meters measure: an ammeter measures current, a voltmeter voltage and an ohmmeter resistance.
- Learn which materials conduct well (silver, copper, aluminium) and which insulate (rubber, glass, plastic).
- At 40 seconds a question there is no time for long working, so practise rearranging Ohm’s law until it is instant.
- If an electrical or electronics job is your goal, ask your recruiter which composite and minimum it needs, since this subtest feeds those scores directly.
Practise Electronics Information on CogniPrep
Our Electronics Information game gives you 15 adaptive questions against the real 10-minute clock: fact questions on components, symbols and units, plus short calculations from schematic diagrams drawn the US way. It adapts from a medium-difficulty start, and questions left unanswered at the end count as random guesses. You get a standard score, where 50 is the average for US 18 to 23 year olds. The questions and their difficulty ratings are ours, so treat the score as a guide.