Question

Explain the following with suitable examples:

Piezoelectric effect

Answer 1

1. The piezoelectric effect is the property of certain crystals to generate an electric voltage when mechanical pressure is applied to them and, conversely, to undergo mechanical deformation when an electric field is applied.
2. This occurs because the centres of positive and negative charges in these crystals do not coincide, and applying pressure disturbs this balance, producing electricity.
3. Example: Quartz (SiO₂) is a common piezoelectric crystal. When sound vibrations apply pressure to it, it produces an electric signal. Conversely, when a voltage is applied, it vibrates at a constant frequency. This property is used in quartz watches, microphones, and ultrasound machines.