Apparatus:
There
are
3
piezoelectricity
demonstrations:
-
Spark
between
2
points.
Turn crank handle with caution so as not to break the crystal. Sparks are generated with compression, and again with release. -
Fan
type.
Plug into AC outlet. Two flaps connected to 2 piezoelectric crystals will oscillate at 60 Hz. -
Hand
held
type.
Hold crystal frame such that it can flex. An attached light bulb has two filaments. One of the filaments will light up with a flex in one direction, and the other will light when the crystal is flexed in the opposite direction.
Description:
These
demonstrations
show
a
change
in
electric
polarization
with
change
in
applied
stress.