Module 3 : MAGNETIC FIELD
Lecture 20 : Magnetism in Matter
  Example 27 :
  Earth receives 1300 watts per squar meter of solar energy. assuming the energy to be in the form of plane electromagnetic waves, compute the magnitude of the electric and magnetic vectors in the sunlight.
  Solution :
From the expression for the average Poynting vector
 
\begin{displaymath}\frac{E_0^2}{2c\mu_0}= 1300\end{displaymath}
  which gives $E_0= 989$ V/m. The corresponding rms value is obtained by dividing by $\sqrt 2$, $E_{rms} = 700$ V/m. The magnetic field strength is $B_{rms}= E_{rms}/c= 2.33\times 10^{-6}$ T.

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