JEE Main 2022 — Electromagnetic Waves Question with Solution

In an electromagnetic wave, the magnitude of the electric field (E) and the magnetic field (B) are related by the speed of the wave (v), which can be represented as :

$$E=Bv$$

Here, B is the magnetic field, E is the electric field, and v is the speed of the electromagnetic wave.

In the given problem, the peak value of the magnetic field is given as :

$$B_0=5\times 10^{-6}T$$

The wave speed (v) can be calculated from the given equation for the magnetic field, using the relationship between frequency (f), wave number (k), and speed :

$$v=\frac{\omega }{k}=\frac{1000\pi \times 4\times 10^8}{1000\pi \times 5}=8\times 10^{7}m/s$$

Substituting these values into the equation for the electric field gives the peak value of the electric field :

$$E_0=B_{0}v=5\times 10^{-6}T\times 8\times 10^{7}m/s=4\times 10^{2}V/m$$