An electromagnetic wave is propagating in a medium with relative permittivity 4 and relative permeability 1 . If the amplitude of the electric field in the wave is 120 V m ⁻¹ , the amplitude of the magnetic field is: (Speed of light in vacuum c = 3 10^8 m s ⁻¹ )

Step-by-step solution

The speed of an electromagnetic wave in a medium is given by: v = c _r _r Substituting the given values for the medium: v = 3 10^8 1 4 = 3 10^8 2 = 1.5 10^8 m s ⁻¹ The relation between the amplitudes of the electric and magnetic fields in the medium is: B₀ = E₀ v Substituting the values: B₀ = 120 1.5 10^8 = 80 10⁻⁸ T = 8 10⁻⁷ T . Answer: 8 10⁻⁷ T