ASVAB Electronics Practice Test 3

Question 1

A transformer has a primary coil with 500 turns and a secondary coil with 100 turns. If the primary voltage is 220V, what is the secondary voltage?

Accepted Answer

44V

Answer

V₂/V₁ = N₂/N₁ → V₂ = 220 × (100/500) = 220 × 0.2 = 44V.

Question 2

In a parallel circuit, three resistors have values of 6Ω, 12Ω, and 4Ω. What is the total resistance?

Accepted Answer

2Ω

Answer

1/Rt = 1/6 + 1/12 + 1/4 = 2/12 + 1/12 + 3/12 = 6/12 = 1/2. So Rt = 2Ω.

Question 3

What does a diode primarily do in an electrical circuit?

Accepted Answer

Allows current to flow in one direction only

Answer

A diode allows current to flow in only one direction (from anode to cathode when forward-biased) and blocks it in the reverse direction.

Question 4

A capacitor with a capacitance of 50 microfarads (µF) is fully charged to 12V. What charge (in microcoulombs) is stored on the capacitor?

Accepted Answer

600 µC

Answer

Q = C × V = 50 µF × 12V = 600 µC.

Question 5

What is the primary difference between NPN and PNP transistors?

Accepted Answer

In NPN, current flows from collector to emitter; in PNP, from emitter to collector

Answer

In an NPN transistor, conventional current flows from collector to emitter (electrons flow emitter to collector). In a PNP, current flows from emitter to collector.

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB Electronics Practice Test 3