Question

If $E_0$ and $B_0$ are the amplitudes of electric and magnetic field vectors in an electromagnetic wave, then the ratio of energy densities due to both fields is

• A. $1:c$
• B. $c:1$
• C. $c^2:1$
• D. $1:1$

Answer 1

The correct option is D $1:1$

The respective energies due to electric and magnetic field is given by,

$u_E=\frac{1}{4}{\epsilon }_0{E}_0^2$

$u_B=\left(\frac{1}{4}\right)\frac{B_0^2}{{\mu }_0}$

So, taking ratio, $u_E:u_B=1:1$