Deep Dive: E3A14
The correct answer is B: Waves with rotating electric and magnetic fields. What are circularly polarized electromagnetic waves is waves with rotating electric and magnetic fields. Circular polarization means the fields rotate as the wave propagates. For amateur radio operators, this is important for understanding polarization. Understanding this helps when working with antennas.
Why Other Answers Are Wrong
Option A: Incorrect. Electric field bent into circular shape isn't circular polarization - circular polarization means rotating fields. Bent shape isn't polarization. Option C: Incorrect. Waves that circle Earth isn't circular polarization - circular polarization means rotating fields. Circling Earth isn't polarization. Option D: Incorrect. Waves produced by loop antenna isn't the definition - circular polarization means rotating fields. Loop antenna isn't the definition.
Exam Tip
Circularly polarized waves = waves with rotating electric and magnetic fields. Think 'C'ircularly 'P'olarized = 'C'ircular 'P'attern (rotating fields). Circular polarization means the fields rotate as the wave propagates. Not bent shape, not circling Earth, not loop antenna - just rotating fields.
Memory Aid
Circularly polarized waves = waves with rotating electric and magnetic fields. Think 'C'ircularly 'P'olarized = 'R'otating fields. Circular polarization means the fields rotate as the wave propagates. Important for understanding polarization.
Real-World Example
Circularly polarized electromagnetic waves: They have rotating electric and magnetic fields. As the wave propagates, the electric and magnetic field vectors rotate in a circular pattern. This is different from linear polarization where fields don't rotate. This is what circularly polarized waves are - waves with rotating fields.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E3A
Reference: 2024-2028 Question Pool · E3 - Radio Wave Propagation
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E3A topic.