Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E6D
E6D01E6D

What is piezoelectricity?

Deep Dive: E6D01

The correct answer is C: A characteristic of materials that generate a voltage when stressed and that flex when a voltage is applied. What is piezoelectricity is a characteristic of materials that generate a voltage when stressed and that flex when a voltage is applied. Piezoelectric materials convert mechanical stress to voltage and vice versa. For amateur radio operators, this is important for component knowledge. Understanding this helps when working with crystals.

Why Other Answers Are Wrong

Option A: Incorrect. Ability to generate electromagnetic waves when voltage applied isn't piezoelectricity - piezoelectricity is stress/voltage conversion. Electromagnetic waves isn't piezoelectricity. Option B: Incorrect. Index of refraction depending on polarization isn't piezoelectricity - piezoelectricity is stress/voltage conversion. Refraction isn't piezoelectricity. Option D: Incorrect. Ability to generate voltage when electromagnetic wave applied isn't piezoelectricity - piezoelectricity is stress/voltage conversion. Electromagnetic wave isn't piezoelectricity.

Exam Tip

Piezoelectricity = materials generate voltage when stressed, flex when voltage applied. Think 'P'iezoelectricity = 'P'ressure 'E'lectricity (stress/voltage conversion). Piezoelectric materials convert mechanical stress to voltage and vice versa. Not electromagnetic waves, not refraction, not electromagnetic wave - just stress/voltage conversion.

Memory Aid

Piezoelectricity = materials generate voltage when stressed, flex when voltage applied. Think 'P'iezoelectricity = 'S'tress/'V'oltage conversion. Piezoelectric materials convert mechanical stress to voltage and vice versa. Important for component knowledge.

Real-World Example

Piezoelectricity: It's a characteristic of materials that generate a voltage when stressed and that flex when a voltage is applied. Quartz crystals used in oscillators exhibit piezoelectricity. This is what piezoelectricity is - stress/voltage conversion.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E6D

Reference: 2024-2028 Question Pool · E6 - Circuit Components

Key Concepts

Piezoelectricity Characteristic of materials Generate voltage when stressed Flex when voltage applied

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E6D topic.