Question

In an electromagnetic wave, the amplitudes of magnetic field $\left(B_0\right)$ and electric field $\left(E_0\right)$ in free space are related as :

• A. $B_0=E_0$
• B. $B_0=\frac{E_0}{c^2}$
• C. $B_0=E_0\sqrt{\frac{{ϵ}_0}{{\mu }_0}}$
• D. $B_0=E_0\sqrt{{\mu }_0{ϵ}_0}$

Answer 1

The correct option is D $B_0=E_0\sqrt{{\mu }_0{ϵ}_0}$

We know that
$B_0=\frac{E_0}{c}$
$\frac{B_0}{E_0}=\frac{1}{c}$
As $c=\frac{1}{\sqrt{{\mu }_0{ϵ}_0}}$
$B_0=E_0\sqrt{{\mu }_0{ϵ}_0}$