Definition: When certain crystals become electrically polarized that is electric charges appear on their surface when stressed then this phenomenon is called the piezoelectric effect, or piezoelectricity and the crystals as the piezoelectric crystals.
Examples: Quartz, rochelle salt, tourmaline are piezoelectric substances.
The inverse effect-that these crystals become strained when polarized (i.e. place in an electric field) has also been observed.
Piezoelectric strains are very small, and the corresponding electric fields are very large.
Example. In Quartz a field of 100 V/cm produces a strain of the order of 10-7.
Origin of piezoelectric effect: Continue reading “PIEZOELECTRICITY”