Suppose a 50-kW radio station emits EM waves uniformly in all directions (a) How much energy per second crosses a 1.0m^2 area 100m from the transmitting antenna? (b) What is the rms magnitude of the E field at this point, assuming the station is operating at full power? (c) What is the voltage induced in a 10 m long vertical car antenna at this distance?(adsbygoogle = window.adsbygoogle || []).push({});

(a) if the definition of power is J/s , wouldnt be the energy acrosses that region also 50kW?

(b) I think this is simply [tex] \frac{\Delta U}{\Delta t} = (\epsilon _0)(E^2)(Ac\Delta t)}[/tex]

Since that we have [tex] \frac{\Delta U}{\Delta t} [/tex], which is 50kW, already, we also have the area, speed of EM wave, and the time it takes to travel 100m, so we can just solve for E.

(c) I have no ideas how to start? any ideas?

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# Homework Help: EM wave

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