An electromagnetic wave in a vacuum traveling in the +x direction generated by a variable source initially has a wavelength λ of 235 μm and a maximum electric field emax in the +y direction of 7.70×10−3 v/m . if the period of the wave is then increased by a factor of 2.70, what is the equation of the resulting magnetic field component of the wave?

If the period of the wave is increased by the factor of 2.70, the wavelength of the wave is also increased by a factor of 2.70. So,

The magnetic field component can be written as

The magnetic field is in the z-direction, because the E-field is directed towards +y and the wave is propagating in the +x-direction. The right-hand rule gives us the direction of the B-field.

S is the Poynting vector which gives us the propagation of the wave.

We will use the following relationships

yup its correct its: c) b b