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ASVAB subject guide

Electronics information

Recognize basic electrical quantities, components, and circuit behavior.

Core review

What to study

  • Voltage is potential difference, current is flow, and resistance opposes flow.
  • Recognize common symbols for batteries, resistors, switches, and ground.
  • Distinguish series paths from parallel branches.

Five-question review

Try original electronics information questions.

Attempt each question before opening the answer and explanation.

Question 1

Electrical current is measured in:

  1. Volts
  2. Amperes
  3. Ohms
  4. Watts
Reveal answer and explanation

Correct answer: Amperes

The ampere is the unit of electric current.

Question 2

A 12-volt source drives 2 amperes through a resistor. What is the resistance?

  1. 4 ohms
  2. 6 ohms
  3. 10 ohms
  4. 24 ohms
Reveal answer and explanation

Correct answer: 6 ohms

Using R = V ÷ I, resistance is 12 ÷ 2 = 6 ohms.

Question 3

In a simple series circuit, the current:

  1. Has only one path
  2. Has a different source at each load
  3. Flows only through insulators
  4. Is always zero
Reveal answer and explanation

Correct answer: Has only one path

A series circuit provides one continuous path for current.

Question 4

Which material is generally the best electrical conductor?

  1. Rubber
  2. Glass
  3. Copper
  4. Dry wood
Reveal answer and explanation

Correct answer: Copper

Copper has low electrical resistance and is widely used as a conductor.

Question 5

What is the primary purpose of a fuse?

  1. Increase voltage
  2. Open an overcurrent circuit
  3. Store electric charge
  4. Reverse polarity
Reveal answer and explanation

Correct answer: Open an overcurrent circuit

A fuse melts and opens the circuit when current exceeds its rating.

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