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Sound — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceSound2 Marks
Question
What are ultrasonic waves? Name two animals which produce ultrasonic waves.
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Answer

Ultrasonic waves: Ultrasonic waves include sounds of frequencies above 20,000Hz. These sounds are produced by objects vibrating very rapidly.
Bats and dolphins can produce these sounds.

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