What is the wavelength of light with a frequency of $100\;Hz$?

If $\mu_{0}$ is permeability of free space and $\varepsilon_{0}$ is permittivity of free space,the speed of light in vacuum is given by

In an electromagnetic wave,the electric field vector and magnetic field vector are given as $\vec{E} = E_{0} \hat{i}$ and $\vec{B} = B_{0} \hat{k}$ respectively. The direction of propagation of the electromagnetic wave is along:

Suppose that the electric field amplitude of an electromagnetic wave is $E_{0} = 120 \; N/C$ and that its frequency is $\nu = 50.0 \; MHz$.
$(a)$ Determine $B_{0}, \omega, k,$ and $\lambda$.
$(b)$ Find expressions for $E$ and $B$.

An electromagnetic wave has its electric and magnetic fields given by $\vec{E}(t) = \vec{E}_m \sin(kx - \omega t)$ and $\vec{B}(t) = \vec{B}_m \sin(kx - \omega t)$. If the directions of $\vec{E}_m$ and $\vec{B}_m$ are in the direction of $\hat{i} + \hat{j}$ and $\hat{i} - \hat{j}$ respectively,the unit vector that gives the direction of propagation of the wave is:

The rms value of the electric field of the light coming from the sun is $720 \ N/C$. The average total energy density of the electromagnetic wave is $:-$