Q 12-08-010NEETNEET 2020Top questionEasy
The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is : (c = speed of electromagnetic waves)
Answer: (B) 1 : 1
Average energy densities:
$$u_E = \frac{1}{4}\epsilon_0E_0^2, \qquad u_B = \frac{B_0^2}{4\mu_0}$$
With $B_0 = \dfrac{E_0}{c}$ and $c^2 = \dfrac{1}{\mu_0\epsilon_0}$:
$$u_B = \frac{E_0^2}{4\mu_0c^2} = \frac{1}{4}\epsilon_0E_0^2 = u_E$$
The electric and magnetic fields contribute equally: $1 : 1$.
Solution by Sreeraj P, M.Sc Physics