Answer:
[tex]3.3\cdot 10^{-8}T[/tex]
Explanation:
The relationship between the amplitude of the electric field and the magnetic field in an electromagnetic wave is
[tex]E=cB[/tex]
where
E is the electric field amplitude
B is the magnetic field amplitude
c is the speed of light
For this electromagnetic wave, we have
[tex]E=10 V/m[/tex]
So we can solve the formula to find B:
[tex]B=\frac{E}{c}=\frac{10 V/m}{3\cdot 10^8 m/s}=3.3\cdot 10^{-8}T[/tex]