Electromagnetic Waves as Sinusoidal Waves Video Lessons

Concept

# Problem: The electric field in an electromagnetic wave is in the y-direction by Ey = E0cos(kx – wt), where E0 = 425 N/C.Part a. If the electromagnetic wave is traveling in the x-direction in a vacuum, what is the direction of the magnetic field?Part b. Express the amplitude of the magnetic field, B­0, in terms of E0 and the speed of light c.Part c. Find the intensity of the electromagnetic wave, l, in terms of E0, c, and the permeability of free space u0.

###### FREE Expert Solution

Part a.

In an electromagnetic wave, the magnetic and electric fields are mutually perpendicular to the direction of the propagation of the wave.

Given that E × B is in the direction of the wave's propagation, the magnetic field, B is perpendicular to the electric field, E, and the direction of electromagnetic wave propagation.

In this problem, the electromagnetic wave is propagating in the x-direction.

The electric field is propagating in the y-direction.

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###### Problem Details

The electric field in an electromagnetic wave is in the y-direction by Ey = E0cos(kx – wt), where E0 = 425 N/C.

Part a. If the electromagnetic wave is traveling in the x-direction in a vacuum, what is the direction of the magnetic field?

Part b. Express the amplitude of the magnetic field, B­0, in terms of E0 and the speed of light c.

Part c. Find the intensity of the electromagnetic wave, l, in terms of E0, c, and the permeability of free space u0.