Q.Write down the properties of electromagnetic waves. (Any six)

Electromagnetic waves are transverse, mutually-perpendicular oscillations of E and B travelling at the speed of light, needing no medium, and carrying energy and momentum.

Properties of electromagnetic waves (any six)

1. Transverse nature: $\vec E$ and $\vec B$ oscillate perpendicular to each other, and both are perpendicular to the direction of wave propagation.
2. In phase: $\vec E$ and $\vec B$ reach their maximum and zero values simultaneously (in phase with each other).
3. Speed in vacuum: all EM waves travel at $c=\dfrac{1}{\sqrt{\mu_0\varepsilon_0}}\approx3\times10^8\ \text{ms}^{-1}$; in a medium, $v=c/n$.
4. Amplitude relation: $E_0 = cB_0$ (the ratio of peak electric to peak magnetic field magnitudes equals $c$).
5. No medium required: unlike mechanical waves, EM waves propagate through a vacuum.
6. Carry energy and momentum: described by the Poynting vector; they exert radiation pressure on absorbing/reflecting surfaces. …