Definition check: Piezoelectricity (converse effect) “Piezoelectricity means a slight change in the dimensions of a specimen when an electric field is applied.” Evaluate this statement.

Introduction / Context:
Piezoelectric materials couple mechanical and electrical domains. They exhibit two complementary effects: the direct effect (mechanical stress generating electric charge) and the converse effect (applied electric field producing strain). The statement given refers to the converse piezoelectric effect.

Given Data / Assumptions:

• Material is piezoelectric (e.g., quartz, certain ceramics like PZT, some polymers).
• Electric field within material is below depolarization or breakdown thresholds.
• Small-signal, linear regime so strain is proportional to the applied field.

Concept / Approach:

In the linear regime, strain S is related to electric field E by S = d E (for appropriate tensor components), where d is the piezoelectric coefficient. Thus, applying E results in a small but measurable dimensional change. This is exploited in actuators, precision positioning, and ultrasonics.

Step-by-Step Solution:

Verification / Alternative check:

Devices like piezo buzzers and nanopositioners demonstrate dimensional changes under applied voltage, confirming the statement.

Why Other Options Are Wrong:

(b) contradicts well-established behavior; (c) references ferromagnets (magnetic phenomenon), not relevant; (d) ignores the converse effect; (e) Curie temperature relates to ferroelectric–paraelectric transition in certain ceramics, not the general definition.

Common Pitfalls:

Assuming all ceramics are piezoelectric (only certain crystal classes are); confusing magnetostriction (magneto-mechanical) with piezoelectricity (electro-mechanical).

Final Answer:

True