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Sound — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceSound3 Marks
Question
What is the difference between supersonic and ultrasonic?
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Answer

The sounds having frequency more than 20,000 hertz (Hz) are called ultrasonic or ultrasound.
The sounds having frequency less than 20Hz are called infrasonic or infrasound.
Both of these sounds cannot be heard by human beings. The audible range for of hearing by human beings is 20Hz to 20000Hz.
The speed of sound is same for all frequencies in a particular medium. So, speed of ultrasonic sound and infrasonic sound are same in a particular medium.

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