Free ASVAB Electronics Information Practice Test
The ASVAB Electronics Information Practice Test helps you review the basic electricity and electronics concepts tested on the EI subtest.
You may need to identify a circuit part, calculate current or voltage, recognize what a meter measures, or decide how a component works.
ASVAB Electronics Information Practice Test
ELECTRONIC BASE
What You Need to Know for Electronics
Information
Electronics Information measures your understanding of electricity, circuits, components,
electrical units, and basic electronic systems.
Source
A battery, cell, or generator supplies electrical energy or potential difference.
Path
Conductors provide a complete route for electric current to move through the circuit.
Control
Switches and other devices open, close, or change the path available to current.
Load
A lamp, motor, heater, or resistor uses electrical energy to perform work.
CURRENT TEST FORMAT
Electronics Information Test Format
The CAT-ASVAB and paper ASVAB use different question counts and time limits.
| Test Version | Questions | Time Limit | Approx. Time |
|---|---|---|---|
| CAT-ASVAB | Questions 15 scored | Time Limit 10 minutes | Approx. Time About 40 sec |
| Paper ASVAB | Questions 20 | Time Limit 9 minutes | Approx. Time About 27 sec |
The CAT-ASVAB may include unscored tryout questions. When they are included, extra time is added to the subtest.
CORE ELECTRICAL QUANTITIES
Start With Voltage, Current, and Resistance
Many EI questions become easier once you can separate these three ideas and match each one with
the correct unit.
Voltage
Voltage is electrical potential difference. It is measured in volts and provides the push that can move charge through a circuit.
Current
Current is the flow of electric charge. It is measured in amperes, or amps.
Resistance
Resistance opposes current flow. It is measured in ohms and is commonly shown with the symbol Ω.
OHM’S LAW
Use Ohm’s Law Without Guessing
Ohm’s Law connects voltage, current, and resistance. Rearrange the same relationship depending on
what the question asks.
I = V ÷ R and R = V ÷ I
If a circuit has 12 volts across a 4-ohm resistor, current is 12 ÷ 4 = 3 amps.
CIRCUIT TYPES
Series and Parallel Circuits Behave
Differently
Before doing any circuit calculation, decide whether the components are connected in one path or
several branches.
Series Circuit
A series circuit has one current path. The same current passes through each component, and a break anywhere can stop the entire circuit.
Total resistance increases as more resistance is added in series.
Parallel Circuit
A parallel circuit has two or more branches. The voltage across the branches is the same, while current divides between them.
One open branch does not always stop current through the other branches.
COMPONENT FUNCTIONS
Learn What Common Electronic
Components Actually Do
Knowing a component name is useful, but knowing its job makes diagram and function
questions much easier.
Resistor
Limits or controls current. Resistance is measured in ohms.
Capacitor
Stores electric charge and energy in an electric field and can charge.
Diode
Allows current to pass more easily in one direction than the other.
Transistor
Can be used to switch or control electronic signals and current.
Switch
Opens, closes, or changes a conducting path in a circuit.
Cell or Battery
Provides electrical energy or potential difference to a circuit.
MEASURMENT TOOLS
Match the Meter With the Quantity
EI questions often test whether you can connect the instrument name with what it measures.
Ammeter
Measures Current
Voltmeter
Measures Voltage
Ohmmeter
Measures Resistance
CURRENT TYPE
Understand AC and DC
AC and DC describe how current behaves, not simply whether the voltage is high or low.
Direct Current
DC flows in one direction. Batteries are a common DC source.
Alternating Current
AC changes direction periodically. Household electrical systems commonly use AC.
FREQUENCY
Know the Common Frequency Units
Frequency tells you how often a repeating cycle occurs. One hertz means one cycle per second.
Hz
Measures Current
kHz
1,000 Hz
MHz
1,000,000 Hz
GHz
1,000,000,000 Hz
POWER AND ENERGY
Do Not Mix Up Watts and Kilowatt-Hours
Power tells you how quickly electrical energy is being used. Energy use over time is a different quantity.
P = V × I
Electrical Power
Power is measured in watts. A 10-volt device drawing 2 amps uses 20 watts.
kWh
Electrical Energy
Kilowatt-hours measure energy used over time, which is why household electricity use is billed in kWh.
MATERIALS AND PROTECTION
Know How Current Is Guided and
Controlled Safely
Conductors, insulators, grounding, and circuit protection all affect where current can flow and what
happens during a fault.
Conductors and Insulators
Copper and other metals conduct electricity well. Rubber and many plastics resist charge movement and are used as insulation around wires.
Electrical Energy
Fuses and circuit breakers open a circuit when current becomes unsafe. Grounding provides a controlled path that can help protect people and equipment during faults.
RECOGNITION SKILLS
Be Ready for Circuit Symbols and Resistor
Color Codes
Some EI questions use diagrams instead of describing every component in words.
Common symbols to recognize
- Cell or battery
- Resistor
- Variable resistor
- Capacitor
- Diode
- Switch
- Ground
- Lamp and motor
Basic resistor color digits
- Black 0
- Brown 1
- Red 2
- Orange 3
- Yellow 4
- Green 5
- Blue 6
- Violet 7
- Gray 8
- White 9
MILITARY JOB SCORES
Electronics Information Does Not Determine
Your AFQT
EI is not part of the AFQT formula. The AFQT uses Arithmetic Reasoning, Mathematics Knowledge,
Word Knowledge, and Paragraph Comprehension.
EI can still contribute to technical or electrical composite scores used by military services when they
evaluate qualification for certain occupations.
THE PACE
Build Speed Without Skipping Units
The standard CAT Electronics Information section gives about 40 seconds per scored question on average.
Identify the task
Decide whether the question asks about a component, circuit, formula, unit, or diagram.
Recall the rule
Use the correct relationship before plugging in numbers.
Check the units
Make sure amps, volts, ohms, watts, or hertz match what the question asks.
Choose and move on
Compare the result with the choices and avoid spending too long on one item.
REVIEW MISTAKE
Sort Electronics Errors by Type
A wrong answer becomes more useful when you know what caused it.
FAQs