Find Magnetic Field Amplitude from EM Wave Amplitude

tquiva
Messages
19
Reaction score
0

Homework Statement



A plane electromagnetic wave propagating in free space has an amplitude (\sqrt{3}/2)a_{y}-(1/2)a_{z} V/m. Find the amplitude of the accompanying magnetic field assuiming the frequency of the electric field is 1 GHz.

Homework Equations



f_{E} = f_{H}

\frac{E_{0}}{B_{0}} = \frac{ω}{k} = c

The Attempt at a Solution



I know that the frequency for both the Electric and Magnetic fields are equivalent. Therefore, the magnetic field frequency is also 1 GHz.

However, the question says "electromagnetic wave." This term means the cross product result or E x B right? With that being said, I'm not sure how to obtain the amplitude of the magnetic field if I don't have any info for the electric field.

Or is there some other equation related to the EM wave?

Any help or suggestions is greatly appreciated!
 
Physics news on Phys.org
tquiva said:
..., the question says "electromagnetic wave." This term means the cross product result or E x B right? With that being said, I'm not sure how to obtain the amplitude of the magnetic field if I don't have any info for the electric field.
But you are provided with "info for the electric field": the frequency and the amplitude. What else do you need?

For EM radiation the E and B components have a special relationship.
 
tquiva said:

Homework Statement



A plane electromagnetic wave propagating in free space has an amplitude (\sqrt{3}/2)a_{y}-(1/2)a_{z} V/m.

Perhaps it was meant the vector amplitude of the electric field.

ehild
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top