<prompt> Which of the follow ing techniques use piezoelectric crystals?UltrasonographyX-ray diffractionNMR imagingXeroradiography  <response>: Ans. is a i.e.. Ultrasonography Ref: Sutton 6the p. 12: Grainger 4thep. 102o Ultrasonography is based on piezoelectric effect.o MR! is based on gyeromagnetic property of proton H. 