Electronics Information practice: ASVAB circuit questions
Ten questions in two sets of five on current, voltage, resistance, power, conductors and components such as diodes, capacitors and transformers. Most need one formula and one line of arithmetic.
Correct answers
0 / 5
0 of 5 answered: the explanations appear below as you go.
| Subtests covered | EI |
Practice items written by Radif Partners for this site, not real ASVAB questions. A share of correct answers does not convert into a standard score or an AFQT percentile.
Prepared by Radif Partners · Method · official sources read on October 22, 2026 · published formulas and tables
Electronics Information (EI) is the ASVAB subtest on electricity and electronic components: Ohm's law, series and parallel circuits, power, units, conductors, and parts such as diodes, capacitors and transformers. The computer version gives 15 questions in 10 minutes, about 40 seconds each, and the paper version 20 questions in 9 minutes, about 27 seconds each, so formulas must come without thinking. EI is not part of the AFQT. It decides access to technical jobs: it is one of the four parts of the Air Force Electrical area (GS + AR + MK + EI) and appears in 2 Marine Corps line scores, MM = AR + MC + EI + AS and EL = GS + AR + MK + EI. A candidate with strong math, AR 55 and MK 56, but EI 42, reads an Electrical percentile of 56; at EI 51 it becomes 67, and the Marine EL rises from 103 to 109. The ten questions are written by Radif Partners, not taken from the ASVAB, and a count of right answers does not convert into a score.
What Electronics Information asks
The ten questions on this page split between calculations and knowledge. Calculations: the current through a resistor from its voltage, a parallel pair and a series chain of resistors, the power of a heater from amps and volts, and the output of a transformer. Knowledge: the unit of power, the best conductor among four metals, the part that lets current flow one way, the voltage of a U.S. wall outlet and the part that stores energy between two plates. The Official ASVAB sample questions show the same mix of short items.
Little time per item
According to the Official ASVAB fact sheet, EI has 15 questions in 10 minutes on the computer test and 20 in 9 minutes on paper, about 40 and 27 seconds per item. That leaves room for one formula and one product, not for deriving the formula. Learn Ohm's law as a triangle with V on top and I and R below: cover the unknown and the remaining two show whether to multiply or divide. A 12 volt battery across 4 ohms gives 12 ÷ 4 = 3 amperes.
Classic traps
- Parallel resistance. Two resistors of 6 and 3 ohms in parallel give 2 ohms, less than either one. If your answer is larger than the smallest resistor, you added them as if they were in series. For two resistors, product over sum works: 18 ÷ 9 = 2.
- Series resistance. Three 10 ohm resistors in series simply add to 30 ohms. Do not divide.
- Power or resistance. P = V × I and V = I × R look alike. A heater drawing 5 amperes at 120 volts uses 600 watts; dividing would give 24, which is a resistance in ohms, not a power.
- Transformer direction. More turns on the secondary means higher voltage: 100 turns to 500 turns multiplies 24 volts by 5, giving 120 volts. Fewer turns would lower it.
- Best conductor. Silver conducts better than copper. Copper is used in wiring because it costs far less, which makes it the tempting wrong answer.
Where EI counts
EI has no effect on the AFQT, but it is one of the four parts of the Air Force Electrical area and appears in the Marine Corps MM = AR + MC + EI + AS and EL = GS + AR + MK + EI line scores, all computed with the formulas and tables of the 1997 score scale report. Take a candidate with AR 55, MK 56, GS 53, MC 50, AS 46 and VE 50. With EI 42, the Electrical percentile is 56, the Marine MM 96 and the Marine EL 103. With EI 51, they become 67, 101 and 109. For someone aiming at avionics, communications or electrical work, that gap can decide which jobs are on the list. The Air Force job finder shows careers with an Electrical minimum, and the Marine Corps page computes all four line scores.
How to prepare
Start with the units and the three formulas above, then the components: resistor, capacitor, inductor, diode, transistor, transformer, fuse and circuit breaker, each with one line on what it does and its schematic symbol. Practice series and parallel problems until you can spot the configuration at a glance. When a question describes a circuit in words, sketch it on your scratch paper: a quick drawing shows at once whether the resistors share both ends, which means parallel, or follow one another, which means series. The Electrical area also uses General Science, so review the physics part of the General Science page; the Marine MM score adds Mechanical Comprehension, covered on the Mechanical Comprehension page. Take the mixed practice test to see how EI compares with your other subtests.