JEE MainPhysicsElectromagnetic Waves
The magnetic field of an electromagnetic wave in vacuum is given by the equation B_y = 3 10⁻⁸ ( t - kx) T . The maximum value of the electric field in the wave is: (Speed of light in vacuum c = 3 10^8 m s ⁻¹ )
Options
- A10⁻¹⁶ V m ⁻¹
- B9 2 V m ⁻¹
- C9 V m ⁻¹
- D27 10⁻⁸ V m ⁻¹
Correct answer
C. 9 V m ⁻¹
Step-by-step solution
The standard equation for the magnetic field of an electromagnetic wave is B_y = B₀ ( t - kx) . Comparing the given equation with the standard form, the amplitude (maximum value) of the magnetic field is B₀ = 3 10⁻⁸ T . The relation between the maximum value of the electric field E₀ and the magnetic field B₀ in vacuum is: E₀ = c B₀ Substituting the values: E₀ = (3 10^8 m s ⁻¹) (3 10⁻⁸ T ) = 9 V m ⁻¹ . Answer: 9 V m ⁻¹