Peak value of magnetic field is 20 nT for an electromagnetic wave.
The magnetic field formula contains the constant^{\mu_{0}}. This is known as permeability of free space and has a value^{\mu}_{0} = 4\pi \times 10^{-7} (T \cdot m/ A). Besides, the unit of a magnetic field is Tesla (T).
The electric field and magnetic field of an electromagnetic wave are perpendicular (at right angles) to each other. They are also perpendicular to the direction of the EM wave. EM waves travel with a constant velocity of 3.00 x 108 ms-1 in vacuum.
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