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8th Class Science Sound Question Bank Self Test-2

  • question_answer
    There are some sounds which cannot be heard by human ear. These sounds have frequency, either more than 20 kHz or less than 20 Hz The sound whose frequency is less than the 20 Hz is called _______.

    A)  Ultrasonic sound

    B)  Infrasonic sound

    C)  Plane sound

    D)  Sonic boom

    E)  None of these

    Correct Answer: B

    Solution :


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