Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E5D
E5D05E5D

What parasitic characteristic causes electrolytic capacitors to be unsuitable for use at RF?

Deep Dive: E5D05

The correct answer is C: Inductance. What parasitic characteristic causes electrolytic capacitors to be unsuitable for use at RF is inductance. Electrolytic capacitors have significant lead inductance, making them unsuitable for RF. For amateur radio operators, this is important for component selection. Understanding this helps when choosing capacitors for RF circuits.

Why Other Answers Are Wrong

Option A (Skin effect): Incorrect. Skin effect isn't the parasitic characteristic - inductance is. Skin effect isn't the cause. Option B (Shunt capacitance): Incorrect. Shunt capacitance isn't the parasitic characteristic - inductance is. Shunt capacitance isn't the cause. Option D (Dielectric leakage): Incorrect. Dielectric leakage isn't the parasitic characteristic - inductance is. Dielectric leakage isn't the cause.

Exam Tip

Electrolytic capacitor unsuitable at RF = inductance parasitic characteristic. Think 'E'lectrolytic 'C'apacitor = 'E'xcessive 'C'onductor inductance. Electrolytic capacitors have significant lead inductance, making them unsuitable for RF. Not skin effect, not shunt capacitance, not dielectric leakage - just inductance.

Memory Aid

Electrolytic capacitor unsuitable at RF = inductance parasitic characteristic. Think 'E'lectrolytic 'C'apacitor = 'I'nductance. Electrolytic capacitors have significant lead inductance, making them unsuitable for RF. Important for component selection.

Real-World Example

Electrolytic capacitors: They're unsuitable for use at RF because of inductance. The long leads and construction of electrolytic capacitors create significant inductance, which becomes problematic at RF frequencies. This is the parasitic characteristic - inductance.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E5D

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

Key Concepts

Parasitic characteristic Electrolytic capacitors Unsuitable for use at RF Inductance

Verified Content

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