An electromagnetic wave of intensity 50 Wm − 2 enters in a medium of refractive index 'n' without any loss. The ratio of the magnitudes of electric fields, and the ratio of the magnitudes of

Question

An electromagnetic wave of intensity 50 Wm − 2 enters in a medium of refractive index 'n' without any loss. The ratio of the magnitudes of electric fields, and the ratio of the magnitudes of magnetic fields of the wave before and after entering into the medium are respectively, given by :

TestHub · Accepted Answer

The speed of electromagnetic wave in free space is given by C = μ 0 ​ ϵ 0 ​ ​ 1 ​ In medium, v = k ∈ 0 ​ μ 0 ​ ​ 1 ​ … (ii) Dividing equation (i) by(ii), we get ∴ V C ​ = k ​ = n 2 1 ​ ϵ 0 ​ E 0 2 ​ C = intensity = 2 1 ​ ϵ 0 ​ kE 2 v ∴ E 0 2 ​ C = kE 2 v ⇒ E 2 E 0 2 ​ ​ = C kV ​ = n n 2 ​ ⇒ E E 0 ​ ​ = n ​ similarly 2 μ 0 ​ B 0 2 ​ C ​ = 2 μ 0 ​ B 2 v ​ ⇒ B B 0 ​ ​ = n ​ 1 ​

Physics - EM Waves Question with Solution | TestHub

Options:

Doubts & Discussion