Re: Why we need modulation?

If you transmit an audio signal (e.g 20 Hz to 20 Khz ), why you keep considering about the speed of light? Isn't it perfect to consider only for electromagnetic waves?

Wavelength= Speed of light/ Frequency
should be used when we use an electromagnetic wave (e.g radio wave).
Please justify your answer.

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If you transmit an audio signal (e.g 20 Hz to 20 Khz ), why you keep considering about the speed of light? Isn't it perfect to consider only for electromagnetic waves?

Wavelength= Speed of light/ Frequency
should be used when we use an electromagnetic wave (e.g radio wave).
Please justify your answer.

we know that all em wave travel in with the same speed that is the speed of light

the wavelength is a concern because of rayleigh's scattering we increase the wavelength to accomadate that