MCQ Detailed View

Sound is a mechanical wave that is produced by vibrations. It requires a material medium such as air, water, or solids to propagate. When an object vibrates, it creates compressions and rarefactions in the surrounding particles of the medium. These disturbances transfer energy from one particle to the next, allowing sound waves to travel from the source to the listener.

In a vacuum, there are no particles present to transmit these vibrations. Since sound depends on the movement of particles to propagate, it cannot travel through a vacuum. This is why in space, where there is no air or matter, astronauts cannot hear each other unless they use radios or electronic communication devices.

Sound travels effectively through different mediums:

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  Gases (like air): Sound travels slower because particles are far apart, resulting in a speed of about 343 m/s at 20°C.

  
  


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  Liquids (like water): Sound moves faster than in gases because particles are closer together, roughly 1,480 m/s in water.

  
  


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  Solids (like steel): Sound travels the fastest here, around 5,000 m/s, due to tightly packed particles that transmit vibrations more efficiently.

  
  

This shows that sound can travel through gases, liquids, and solids, but not through empty space. Electromagnetic waves like light or radio waves can travel through a vacuum because they do not require matter, but mechanical waves like sound cannot.The misconception that sound can move without a medium is incorrect. Experiments, such as placing a ringing bell in a vacuum chamber, clearly demonstrate that as air is removed, the sound becomes weaker until it disappears completely.

Hence, the true statement is: Sound cannot travel through a vacuum, making option A the correct answer.