Which of the following statements is or are correct about longitudina...
Longitudinal mechanical waves are waves in which the particles of the medium vibrate in the same direction as the direction of wave propagation. These waves are characterized by compressions and rarefactions, where the particles are pushed together and spread apart, respectively.
a) Audible or sound waves:
- The longitudinal mechanical waves which lie in the frequency range 20 Hz to 20,000 Hz are called audible or sound waves.
- These are the waves that can be detected by the human ear.
- Sound waves are commonly encountered in our daily lives, such as when we hear someone speaking or when we listen to music.
- These waves propagate through various mediums, including air, water, and solids.
b) Infrasonic waves:
- The longitudinal mechanical waves having frequencies less than 20 Hz are called infrasonic waves.
- Infrasonic waves are below the range of human hearing and cannot be detected by the human ear.
- Some animals, such as elephants and whales, can detect and use infrasonic waves for communication and navigation.
- Infrasonic waves can also be produced by natural phenomena like earthquakes and volcanic eruptions.
c) Ultrasonic waves:
- The longitudinal mechanical waves having frequencies greater than 20,000 Hz are called ultrasonic waves.
- Ultrasonic waves are above the range of human hearing and cannot be heard by the human ear.
- These waves have many practical applications, such as in medical imaging (ultrasound), industrial testing, and cleaning.
- Ultrasonic waves can be used to detect flaws in materials, break down dirt particles, and even for non-destructive testing of structures.
d) All of the above are correct:
- The statement is correct because all the mentioned statements about longitudinal mechanical waves are true.
- Audible or sound waves, infrasonic waves, and ultrasonic waves are all different categories of longitudinal mechanical waves based on their frequency ranges.
In conclusion, all the statements (a, b, and c) about longitudinal mechanical waves are correct. Audible or sound waves lie in the frequency range 20 Hz to 20,000 Hz, infrasonic waves have frequencies less than 20 Hz, and ultrasonic waves have frequencies greater than 20,000 Hz.
Which of the following statements is or are correct about longitudina...
- Sound or Audible waves are sensitive to the human ear and are generated by the vibrating bodies like tuning fork, vocal cords etc.
- Infrasonic waves are produced by sources of bigger size such as earthquakes, volcanic eruptions, ocean waves etc. Human ear cannot detect Ultrasonic waves.
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