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EM waves; max value of electric field

  • Thread starter Dx
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Dx

Hello,
What is the max value of the eletric field at a distance 2.5m from 100W light bulb?

I have the formula E_o = [squ]2S/e_oc. This is what i have so far...
E_o = [squ]2(100W)/(8.85x10^-12C^2/Nm^2)(3x10^8m/s) = 274V/m.

My calculations are not right can someone help me with solving for this, plz?

Thanks!
Dx :wink:
 
Last edited by a moderator:
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Originally posted by Dx
Hello,
What is the max value of the eletric field at a distance 2.5m from 100W light bulb?

I have the formula E_o = [squ]2S/e_oc. This is what i have so far...
E_o = [squ]2(100W)/(8.85x10^-12C^2/Nm^2)(3x10^8m/s) = 274V/m.

My calculations are not right can someone help me with solving for this, plz?

Thanks!
Dx :wink:
Wrong equation Dx.
S, the poynting vector, is not the power of the bulb. Rather, Power, P = S(4[pi]r^2). From this you can derive an eqn. which includes r.

Creator
 
Last edited:

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