Question

The energy per unit volume in an electromagnetic wave is: ________

Answer 1

Answer:

c.

Explanation:

Electromagnetic waves are waves that are generated when an electric field and a magnetic field vibrate together. They are usually created whenever an electric field collides with a magnetic field.

In more generic terms for an electric field, the energy per unit volume is given by:

Energy density = $\dfrac{1}{2}\varepsilon _oE^2$

For magnetic field:

Energy density =$\dfrac{\beta^2}{2 \mu _o}$

∴

For the electromagnetic wave (u):

Total energy density is:

$u = \dfrac{1}{2}\varepsilon_oE^2 + \dfrac{\beta ^2}{2 \mu_o}$

Due to the fact that the energy related with both fields is equivalent:

Then:

E = cB