Difficulty: Easy
Correct Answer: False — many dielectrics (especially ferroelectrics) exhibit dielectric hysteresis
Explanation:
Introduction / Context:Polarization in dielectric materials can follow the applied electric field along a path that depends on prior excitation. The presence or absence of hysteresis is crucial in capacitor dielectrics, non-volatile memories, sensors, and actuators.
Given Data / Assumptions:
Concept / Approach:Linear dielectrics follow P = ε0 χ E without hysteresis. However, ferroelectric materials (e.g., BaTiO3, PZT) show spontaneous polarization that can be reversed by an external field, producing a characteristic P–E loop (dielectric hysteresis). Relaxor and some polymer ferroelectrics also show history-dependent response. Thus the blanket statement that no dielectric has hysteresis is false.
Step-by-Step Solution:
Define hysteresis: output (polarization) depends on input history (electric field).Identify classes: linear dielectrics (no hysteresis) vs. ferroelectrics (with hysteresis).Conclude the statement is false due to ferroelectric examples.Verification / Alternative check:
Measure a P–E loop using a Sawyer–Tower circuit; ferroelectrics show remanent polarization and coercive field.Why Other Options Are Wrong:
Options asserting universal absence of hysteresis ignore a large class of materials.Frequency or temperature caveats do not make the universal statement true.Common Pitfalls:
Assuming behavior of ideal capacitors applies to all dielectrics; overlooking ferroelectric phase transitions.Final Answer:
False — many dielectrics (especially ferroelectrics) exhibit dielectric hysteresis
Discussion & Comments