ASVAB Electronics Practice Test 1 2

Question 1

A circuit has a resistance of 10 ohms and a current of 3 amperes flowing through it. What is the voltage across the resistor?

Accepted Answer

30 volts

Answer

Ohm's Law states V = I × R. Substituting the given values: V = 3 A × 10 Ω = 30 volts. Ohm's Law is the most fundamental relationship in electronics, connecting voltage (V), current (I), and resistance (R).

Question 2

What is the primary function of a capacitor in an electronic circuit?

Accepted Answer

To store electrical energy in an electric field and release it

Answer

A capacitor stores energy in the electric field between two conductive plates separated by an insulating material (dielectric). It can charge (store) and discharge (release) energy rapidly, making it useful for filtering, timing, and energy storage applications.

Question 3

In a parallel circuit with three branches, if one branch is open (broken), what happens to the other two branches?

Accepted Answer

The remaining two branches continue to operate normally

Answer

In a parallel circuit, each branch has its own independent path back to the voltage source. If one branch opens (breaks), the other branches are unaffected — they still have complete paths and continue to operate at the same voltage. This is a key advantage of parallel wiring used in homes.

Question 4

A transformer steps voltage up from 120V to 480V. If the primary coil has 200 turns, how many turns does the secondary coil have?

Accepted Answer

800 turns

Answer

The transformer turns ratio formula is: V1/V2 = N1/N2. So N2 = N1 × (V2/V1) = 200 × (480/120) = 200 × 4 = 800 turns. Transformers work on electromagnetic induction and can only operate with AC because DC does not produce a changing magnetic field.

Question 5

Which electronic component allows current to flow in only one direction?

Accepted Answer

Diode

Answer

A diode is a semiconductor device that acts like a one-way valve for electrical current — it conducts in the forward-biased direction and blocks current in the reverse-biased direction. Diodes are used in rectifiers to convert AC to DC, in signal detection, and in protection circuits.

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB Electronics Practice Test 1 2