Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T5A
T5A01T5A

Electrical current is measured in which of the following units?

Deep Dive: T5A01

The correct answer is D: Amperes. Electrical current is measured in amperes (often abbreviated as 'amps' or 'A'). Current is the flow of electric charge (electrons) through a conductor, and the ampere is the standard unit for measuring this flow rate. One ampere represents one coulomb of charge flowing past a point per second. Current is one of the fundamental electrical quantities, along with voltage and resistance. When you see specifications like '12 amperes' or '5A', that's referring to electrical current. Understanding current is essential for amateur radio, as you need to know how much current your equipment draws to properly size power supplies, fuses, and wiring.

Why Other Answers Are Wrong

Option A: Incorrect. Volts measure voltage (electrical pressure), not current. Voltage and current are different quantities. Option B: Incorrect. Watts measure power (the rate of energy use), not current. Power = Voltage × Current. Option C: Incorrect. Ohms measure resistance (opposition to current flow), not current itself.

Exam Tip

Current = Amperes. Remember: Electrical current is measured in amperes (A). Think 'Current flows in Amperes'.

Memory Aid

**C**urrent = **A**mperes (think 'C = A' = Current = Amperes)

Real-World Example

Your transceiver draws 12 amperes when transmitting at full power. This means 12 amperes of current flow through the power wires from your battery to the transceiver. You need to ensure your power supply and wiring can handle at least 12 amperes. If you use wire that's too thin, it might overheat with this much current.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T5A

Reference: FCC Part 97.3

Key Concepts

Electrical current Amperes Current measurement Electrical units

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T5A topic.