An electromagnetic wave has an average intensity of 15 W m ⁻² . The peak value of the magnetic field of this wave is (Given c = 3 10^8 m s ⁻¹ and ₀ = 4 10⁻⁷ T m A ⁻¹ )

Step-by-step solution

The average intensity I of an electromagnetic wave is related to the peak magnetic field B₀ by the formula: I = 1 2 c ₀ B₀^2 Rearranging for B₀^2 , we get: B₀^2 = 2 ₀ I c Substituting the given values: B₀^2 = 2 (4 10⁻⁷) ( 15 ) 3 10^8 B₀^2 = 120 10⁻⁷ 3 10^8 = 40 10⁻¹⁵ = 4 10⁻¹⁴ T ^2 Taking the square root gives the peak magnetic field: B₀ = 2 10⁻⁷ T Answer: 2 10⁻⁷ T