If the electric field in an EM wave in free space has a peak magnitude of 8.1×10−5V/m, what is the peak magnitude of the magnetic field strength? Express your answer using two significant figures.

2.7 * 10⁻¹³ T

Explanation:

The electromagnetic wave is produced when an oscillating electric and magnetic field interacts each other perpendicularly.

In an electromagnetic wave, the electric field peak magnitude E and the magnetic field peak magnitude B are related by

where ,

c = 3 * 10⁸m/s

E = 8.1×10−5V/m

the peak magnitude of the magnetic field:

2.7 * 10⁻¹³ T

the answer is definitely c.