If we put a cardboard (say 20 cm x 20 cm) between a light source and our eyes, we can’t see the light. But when we put the same cardboard between a sound source and our ear, we hear the sound almost clearly. Explain.

We know that light travels in straight lines. Also, the wavelength of light is quite small in comparison to sound waves. Hence, the phenomena of diffraction are minimum in light and we only see a faint glow and not the true brightness. But in case of sound waves, the wavelength is considerable and so is the diffraction. Sound waves transfer their energy through eh particles in the medium and hence are spread more. This is why we are able to hear the sound source even after keeping an obstruction between the source and the listener.


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