Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E5D
E5D06E5D

What parasitic characteristic creates an inductor’s self-resonance?

Deep Dive: E5D06

The correct answer is D: Inter-turn capacitance. What parasitic characteristic creates an inductor's self-resonance is inter-turn capacitance. The capacitance between turns of an inductor creates self-resonance. For amateur radio operators, this is important for understanding inductor behavior. Understanding this helps when working with inductors.

Why Other Answers Are Wrong

Option A (Skin effect): Incorrect. Skin effect isn't what creates self-resonance - inter-turn capacitance is. Skin effect isn't the cause. Option B (Dielectric loss): Incorrect. Dielectric loss isn't what creates self-resonance - inter-turn capacitance is. Dielectric loss isn't the cause. Option C (Coupling): Incorrect. Coupling isn't what creates self-resonance - inter-turn capacitance is. Coupling isn't the cause.

Exam Tip

Inductor self-resonance cause = inter-turn capacitance. Think 'I'nductor 'S'elf-'R'esonance = 'I'nter-turn 'C'apacitance. The capacitance between turns of an inductor creates self-resonance. Not skin effect, not dielectric loss, not coupling - just inter-turn capacitance.

Memory Aid

Inductor self-resonance cause = inter-turn capacitance. Think 'I'nductor 'S'elf-'R'esonance = 'I'nter-turn 'C'apacitance. The capacitance between turns of an inductor creates self-resonance. Important for understanding inductor behavior.

Real-World Example

An inductor's self-resonance: It's created by inter-turn capacitance. The capacitance between adjacent turns of the inductor coil forms a resonant circuit with the inductance. This is the parasitic characteristic - inter-turn capacitance.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E5D

Reference: 2024-2028 Question Pool · E5 - Electrical Principles

Key Concepts

Parasitic characteristic Inductor's self-resonance Inter-turn capacitance Inductor behavior

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E5D topic.