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Homework Help: Electromagnetic radiation from a lamp

  1. Jun 1, 2010 #1
    1. The problem statement, all variables and given/known data

    What is the peak electric field E_0 at 1 m from a 100 W lamp. Assume spherically uniform emission

    2. Relevant equations

    Magnitude of Poynting vector [tex] S = \frac{E_0^2}{c\mu_0} [/tex]
    And Power = S x Area (2)

    3. The attempt at a solution

    Sub for S from (1) in (2) and rearranging: [tex] E_0 = \sqrt{\frac{cP\mu_0}{A}} [/tex]

    is A just then [tex] 4\pi d^2 [/tex] where d = 1m?

    Then after that just plugging in numbers?
  2. jcsd
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