Certain crystals produce electric signals on application of pressure. This phenomenon is called

a. Pyroelectricity

b. Ferroelectricity

c. Peizoelectricity

d. Ferrielectricity

Ans. c

Explanation : When polar crystal is subjected to a mechanical stress, electricity is produced a case of piezoelectricity. Reversely if electric field is applied mechanical stress is developed. Piezoelectric crystal acts as a mechanical electrical transductor