Which of the following is an aspect of the piezoelectric effect?

The piezoelectric effect is a reversible process found in materials like quartz crystals. It describes the direct relationship between physical mechanics and electricity. One core aspect of this effect is that applying a voltage across the material causes it to mechanically deform, flex, or change shape. This is the precise mechanism that allows a crystal oscillator to vibrate at a specific frequency when an alternating current is applied. Distractors involving magnetic fields refer to a different phenomenon called magnetostriction. Options involving the generation of energy or increased conductivity in the presence of light describe the photovoltaic and photoelectric effects, not piezoelectricity.