Q.Electromagnetic waves are :

Electromagnetic waves share a set of defining properties that follow directly from Maxwell's equations. They are transverse waves: the electric field $\vec{E}$ and magnetic field $\vec{B}$ are always mutually perpendicular, and both are perpendicular to the direction of propagation, with that direction itself given by the cross product $\vec{E}\times\vec{B}$ (which also represents the energy flow of the wave). The two fields vary sinusoidally in phase, reaching their maxima and minima together, and they need no material medium -- EM waves travel through vacuum as readily as through solids, liquids or gases, obeying the principle of superposition like any other wave. …