Question

Which of the following statements is an accurate description of vibrations? A. Ultrasonic vibrations have a frequency lower than the range for normal hearing. B. Infrasonic vibrations are used in sonar equipment as well as to detect flaws in steel castings. C. The frequency of infrasonic vibrations is much too high to be heard by humans. D. Neither ultrasonic nor infrasonic vibrations can be heard by humans.

Answer 1

D: Neither ultrasonic nor infrasonic vibrations can be heard by humans.

Answer 2

Answer

D. Neither ultrasonic nor infrasonic vibrations can be heard by humans.

Explanation

Human hearing is somehow limited. Frequencies below 20 Hz cannot be heard by human and sounds of frequencies above 20,000 Hz too. The sounds of frequency below 20 Hz are known as the infrasonic sounds. Those above 20,000 Hz are called Ultrasonic sounds.