Physics - EM Waves Question with Solution | TestHub

${\left(\frac{U}{\mathrm{V}}\right)}_{\mathrm{elec}}=\frac{1}{2}{\in }_0{E}^2$      ....(i)

${\left(\frac{U}{\mathrm{V}}\right)}_{\mathrm{mag}}=\frac{1}{2}{\mathrm{B}}^2/{\mathrm{\mu }}_0$     ....(ii)

$\text{B}=\frac{\text{E}}{\text{C}}$ (for EMW)         ....(iii)

and $C=\frac{1}{\sqrt{{\mu }_0{\epsilon }_0}}$ .....(iv)

∴ devide eqⁿ (i) by (ii) 

$\frac{{(U/V)}_{elec}}{{(U/V)}_{mag}}=\frac{{\displaystyle \frac{1}{2}}{\epsilon }_0{E}^2}{\frac{1}{2}{B}^2/{\mu }_0}$

$={\left(\frac{E}{B}\right)}^2{\mu }_0{\epsilon }_0$

by using eq (iii) & (iv)

$=\frac{C^2}{C^2}=1$

$\Rightarrow {(U/V)}_{elec.}={\left(\frac{U}{V}\right)}_{mag}$