the electromagnetic waves that deliver a wireless phone call to your cell phone

Question

the electromagnetic waves that deliver a wireless phone call to your cell phone have a magnetic field with and RMS value of .15 nano-Tesla. the waves pass through an integrated antenna perpendicularly whose area is 0.02m^2
a) calculate how much energy this wave delivers to the cell phone antenna for a call of 5 minute duration.
b) what will be RMS value of electric field associated with the wave whose magnetic field value is given above (0.15 nano-Tesla)

hint: consider using formula for intensity S in terms of B field and also the definition of intensity as related to the energy density u. A relation. E=cB may also be useful

Explanation / Answer

H = B/u= (.15E-9)/(4pE-7) = 1.19E-4 I = .5Zo*H^2 Where Z0 = free space impedance = 376.73 ohm I = .5 (376.73)(1.19E-4)^2 = 2.68E-6 Energy = IAt = (2.68E-6)(.02)(300 second) = 1.61E-5 J Part b) E = cB = (3E8)(.15E-9) = .045 V/m

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