how to show the relation between amplitude and distance in electromagnetic radiation??help me?

Answer 1

distance is related to the frequency of the wave.That is, it is closely related to the time period.Amplitude is the maximum level the wave goes

Answer 2

It really is not that easy. Amplitude is not at issue in a transmitter, good old fashioned watts are at issue, as well as the efficiency of the radiator, or antenna. Is the antenna full wave, or quarter, or half wave. Is it vertical, horizontal, beam, parabolic, or a long wire Marconi. All of these are relevant factors. You can have a high amplitude signal going into your antenna, but very little power. So, there are other things you need to know before you start working out how far that signal will go. You also need to know the frequency of the signal. High frequency may go literally around the world, while a VHF, or UHF signal won't get out of the city. VHF, and UHF frequencies are considered to be line of sight dependent frequencies. Line of sight, however, also needs to take into consideration just how high the broadcasting tower is. Line of sight increases as the tower height goes up. You will need to use the inverse square law to figure what your signal strength will be as you move away from the antenna. It doesn't take very long before Mega Watts is micro watts, or less.