Ultrasonic or Supersonic is the study of pressure waves which are of the same nature of the sound waves of very high frequency above the range of human audibility. Human hearing range is 16 to 20,000 Hz (Hertz). But ultrasound range is 21 to 101, 000 Hz. Ultrasound can be produced by using restrictive and pies electric, methods.
Uses of Ultrasonic:
(i) Sonar:
It is low-frequency ultrasonic beam used for underwater observation, communication and navigation in the study of oceanography. The sonar can penetrate deep into the ocean and be reflected back from an obstacle there; thus giving detail underwater information's. The bottom of the ocean can be mapped properly by using an echo-sounder. The locations and proper positioning of enemy vessels can also be detected using military sonar's.
(ii) Industry:
In industry ultrasonic waves are widely employed for quality control testing. When a short pulse of ultrasound is sent into a metal, it is immediately reflected back from cracks and blow nous if any present. Along with light, sound wave is used in acoustic holography for advanced technological implications.
(iii) Medicine:
For diagnosis of diseases and getting knowledge about internal organs 'ultrasonography' is used widely in medical science at present time. This technique is mostly employed to locate and define brain tumors, to locate the position of placenta and" fetus during pregnancy, to detect stones in gall bladder and kidneys and to identify the site and severity of arterial obstruction. The instrument used for these purposes is "ultrasonoscope."