Answer:
the magnitude of the magnetic field is 1.23 × 10⁻⁸ T { in the +y direction }
Step-by-step explanation:
Given the data in the question;
the relation between the electric field and the magnetic field in an electromagnetic wave can be written as follows;
c = E₀/B₀
where c is speed of light, E₀ is the amplitude of the electric field and B₀ is the amplitude of the magnetic field.
given that; E₀ = 4.70 V/m, we know that; speed of light c = 3 × 10⁸ m/s
so from our relation; c = E₀/B₀
B₀ = E₀/c
we substitute
B₀ = 4.70 / 3 × 10⁸
B₀ = 1.23 × 10⁻⁸ T { in the +y direction }
Therefore, the magnitude of the magnetic field is 1.23 × 10⁻⁸ T { in the +y direction }