An electromagnetic wave of intensity 50 W m^ | vedclass

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(D) The intensity of an electromagnetic wave is given by $I = \frac{1}{2} \epsilon_0 E^2 c$. Since the intensity remains constant as it enters the med

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$\left( \sqrt{n}, \frac{1}{\sqrt{n}} \right)$

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(D) The intensity of an electromagnetic wave is given by $I = \frac{1}{2} \epsilon_0 E^2 c$. Since the intensity remains constant as it enters the medium,$I_i = I_f$.Thus,$\frac{1}{2} \epsilon_0 E_i^2 c = \frac{1}{2} \epsilon E_f^2 v$,where $v = \frac{c}{n}$ and $\epsilon = n^2 \epsilon_0$.$\epsilon_0 E_i^2 c = (n^2 \epsilon_0) E_f^2 (\frac{c}{n}) \Rightarrow E_i^2 = n E_f^2 \Rightarrow \frac{E_i}{E_f} = \sqrt{n}$.For magnetic fields,$B = \frac{E}{v}$.$\frac{B_i}{B_f} = \frac{E_i / c}{E_f / v} = \frac{E_i}{E_f} \cdot \frac{v}{c} = \sqrt{n} \cdot \frac{1}{n} = \frac{1}{\sqrt{n}}$.Therefore,the ratios are $\left( \sqrt{n}, \frac{1}{\sqrt{n}} \right)$.

An electromagnetic wave of intensity $50 \ W m^{-2}$ enters a medium of refractive index $n$ without any loss. The ratio of the magnitudes of electric fields and the ratio of the magnitudes of magnetic fields of the wave before and after entering the medium are respectively given by:

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