Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T3B
T3B02T3B

What property of a radio wave defines its polarization?

Deep Dive: T3B02

The correct answer is A: The orientation of the electric field. The polarization of a radio wave is defined by the orientation of the electric field. If the electric field is vertical, the wave is vertically polarized. If the electric field is horizontal, the wave is horizontally polarized. The polarization is determined by how the transmitting antenna is oriented, which determines the orientation of the electric field in the radiated wave. A vertical antenna produces a vertically polarized wave (electric field vertical). A horizontal antenna produces a horizontally polarized wave (electric field horizontal). The magnetic field is always perpendicular to the electric field, so once you know the electric field orientation, the magnetic field orientation is determined.

Why Other Answers Are Wrong

Option B: Incorrect. While the magnetic field is related, polarization is specifically defined by the electric field orientation, not the magnetic field. Option C: Incorrect. The ratio of magnetic to electric field energy doesn't define polarization. Polarization is about orientation, not energy ratios. Option D: Incorrect. The ratio of velocity to wavelength doesn't define polarization. That's related to frequency, not polarization.

Exam Tip

Polarization = Electric field orientation. Remember: Wave polarization is defined by the orientation of the electric field. Vertical E-field = vertical polarization, horizontal E-field = horizontal polarization.

Memory Aid

**P**olarization = **P**rimary **E**lectric (think 'P = PE' = Primary Electric field orientation)

Real-World Example

You're using a vertical antenna on 2 meters. This antenna produces a vertically polarized wave - the electric field oscillates vertically. When you switch to a horizontal antenna, the wave becomes horizontally polarized - the electric field oscillates horizontally. The polarization follows the electric field orientation, which follows the antenna orientation.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T3B

Reference: FCC Part 97.3

Key Concepts

Polarization Electric field Antenna orientation Radio waves

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T3B topic.