The two resistors are in series across an ideal 12 V source. What is the voltage across the 9 Ω resistor?
Choose an answer to check it.
ASVAB Electronics Information practice
Learn how a circuit behaves, then connect that behavior to its symbols, components and quantities.
The two resistors are in series across an ideal 12 V source. What is the voltage across the 9 Ω resistor?
Choose an answer to check it.
9,200+ candidates · 101,000+ practice sessions across Game Assessment Prep.
Candidates from 100+ universities and colleges
Sample question and explanation
This original example is free to use without an account and is separate from the scored practice bank.
What to study
- Current, voltage and resistance
- Series and parallel circuits
- Circuit symbols and components
- Electrical power
- Magnets, AC and DC
Methods and lessons
Open a topic to review the method, then practice applying it to a new question.
Distinguish the electrical quantities
Current is the rate of electric charge flow, measured in amperes. Voltage is a potential difference, measured in volts. Resistance relates voltage to current, measured in ohms.
For a resistor obeying Ohm’s law, V = IR. Electrical power is P = VI. Predict the direction of a change before calculating: at fixed voltage, increasing resistance reduces current.
An ideal 12 V source is connected across a 6 Ω resistor. What current flows?
Answer: 2 A.
Use I = V/R. The current is 12 ÷ 6 = 2 amperes. This assumes the stated voltage appears across that resistor.
Trace series and parallel paths
A series circuit has one current path. Series resistances add, and the same current passes through each resistor. In parallel, branches share the same voltage across their endpoints and their currents add.
Follow connections, not the visual position of a symbol. A wire crossing is a connection only when the diagram’s notation indicates one. Opening a switch interrupts the path it belongs to.
Two 8 Ω resistors are connected in parallel across an ideal source. What is their combined resistance?
Answer: 4 Ω.
For two equal resistors in parallel, the equivalent resistance is half of either resistance. Equivalently, 1/R = 1/8 + 1/8 = 1/4.
Identify a component by its job
A resistor limits current or divides voltage in a suitable circuit. A capacitor stores energy in an electric field. A diode allows current much more readily in one direction. A fuse opens a circuit when excessive current melts its element.
Learn each schematic symbol alongside a simple use. Distinguish measuring voltage across a component from measuring current through a path. These diagrams are study models, not instructions for working on energized equipment.
Connect magnetism to electrical systems
Current in a wire produces a magnetic field. Coils concentrate that effect; changing magnetic fields can induce voltage. A transformer uses a changing magnetic field to transfer energy between coils.
Direct current flows in one direction. Alternating current reverses direction periodically. Keep frequency, voltage and power separate: each describes a different property of the system.
Common questions
Is this only Ohm’s law practice?
No. Numerical relationships are one part of Electronics Information. Also study circuit paths, symbols, components, power, magnetism and the difference between AC and DC.
Does Electronics Information affect AFQT?
It is outside the four AFQT subjects, but it can contribute to job qualification composites. Use the current requirements for the service and role you are considering to decide how much study time it needs.
Practice another subject
General ScienceArithmetic ReasoningWord KnowledgeParagraph ComprehensionMathematics KnowledgeAuto InformationShop InformationMechanical ComprehensionAssembling Objects
View full ASVAB practice tests Official references
Original independent practice. Scores show performance on our questions, not an official ASVAB result.