What physical quantity is the same for $X$-rays of wavelength $10^{-10} \; m$,red light of wavelength $6800 \; \mathring{A}$,and radio waves of wavelength $500 \; m$?

In the propagation of electromagnetic waves,the angle between the direction of propagation and the plane of polarisation is......$^o$.

$A$ plane electromagnetic wave of frequency $20 \text{ MHz}$ travels through space along the $x$-direction. If the electric field vector at a certain point in space is $6 \text{ V m}^{-1}$,what is the magnetic field vector at that point?

The electric field and magnetic field associated with an electromagnetic $(e.m.)$ wave,propagating along the $-z$ axis,can be represented by:

$A$ plane electromagnetic wave is incident on a material surface. If the wave delivers momentum $p$ and energy $E$,then

The ratio of the magnitude of the magnetic field $(B_0)$ and electric field intensity $(E_0)$ of a plane electromagnetic wave in free space with permeability $\mu_0$ and permittivity $\varepsilon_0$ is (Given that $c$ is the velocity of light in free space):