Question

A sinusoidal electromagnetic wave is propagating in vacuum in the +z-direction. If at a particular instant and at a certain point in space the electric field is in the +x-direction and has magnitude 3.20 V/m, what are the magnitude and direction of the magnetic field of the wave at this same point in space and instant in time?

Answer 1

Answer:

The magnitude of the magnetic field is $B_o = 1.13 *10^{-8}T$

 The direction is in the +y direction

Explanation:

    From the question we are told that  

      The electric field is $E_o = 3.40 \ V/m$

The relationship between electric and magnetic field is mathematically represented  as

               $c = \frac{E_o}{B_o}$

Where  c is the speed of light

              $B_o$ is the magnetic field

Making $B_o$  the subject off the formula

                $B_o = \frac{E_o}{c}$

                       $= \frac{3.40}{3*10^{8}}$

                 $B_o = 1.13 *10^{-8}T$

Generally in an electromagnetic wave the direction of the wave propagation , the electric field and the magnetic field are perpendicular

   Since from the question the direction of the electric field is +x direction and the  wave  propagation is in the + z direction then the magnetic field would be in the + y direction