All Questions
35
questions
1
vote
0
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16
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Why is the intensity of a beam of light the squared magnitude of the phasor and not just the squared magnitude of the real part?
I'm learning about phasors and light intensity and there are two conflicting things I've been told that I can't reconcile.
Firstly I've been told that a phasor $e^{-ikz+i\phi}$ is a mathematical way ...
- 531
0
votes
2
answers
102
views
Why In an electromagnetic wave both electric and magnetic waves are in sync and perpendeculare? if one makes the other shouldnt there be a delay? [closed]
Why are electric and magnetic waves in phase if one induces the other? Shouldn't there be a delay, similar to how potential energy converts to kinetic energy and vice versa? Additionally, why are ...
- 21
0
votes
2
answers
53
views
Are all recursive interactions between electric and magnetic fields always orthogonal to each other?
ecursively, this implies that changes in the electric field generate the magnetic field, and vice versa, akin to the plane wave solution resulting from specific boundary conditions intentionally ...
- 21
1
vote
1
answer
125
views
Can an electromagnetic wave be polarised in the direction it propagates?
Can the electric field vector of an EM wave oscillate in the propagation direction?
In text books the polarisation is always orthogonal to the propagation direction.
I'm wondering specifically ...
- 21
0
votes
0
answers
27
views
How do the forces involved in EMR continue to occilate past emmision of a photon
If electric fields are created by an accelerated charged particle, such as an electron, and magnetic fields are generated by electric fields in motion, what are the individual fields that make up ...
0
votes
1
answer
91
views
Near field of cylindrical waves
I was wondering what the near-field expression of the Electric field for a cylindrical wave is.
I know that in the case of a spherical wave, as shown in Jackson (9.18), the far field has a 1/r ...
- 11
0
votes
1
answer
79
views
2D and 3D EM wave intensity and amplitude of $\mathbf E$ and $\mathbf B$ fields
For a spherical wave such as light from the sun or a light bulb, we can use the following formula to calculate its intensity:
$$
I ({Watts}/{m^2}) = \frac{P}{4\pi{r^2}}
$$
Given the Sun's power = $4\...
- 191
0
votes
1
answer
219
views
What is the physical significance of crest and trough in an electromagnetic wave?
Lets say an electron is vibrating at its mean position. From what I've gathered a crest would be its motion in one direction and a trough would be its motion in another direction. So first of all is ...
0
votes
2
answers
110
views
Couldn't understand the reasoning on the propagation of the electromagnetic wave in the vacuum?
Since the solution of the wave function in vaccum gives two progressive plane waves $f(x-ct)+g(x+ct)$ depending on $x$ the direction of propagation, in the other side we have the $\operatorname{div}(...
- 15
-1
votes
1
answer
115
views
How to proove that the electromagnetic wave is transverse? [closed]
From the solution of wave equation we got E = f(z+ct)+g(z-ct). How IS the function f or g are transverse?
- 15
0
votes
1
answer
80
views
Virtual photons and slowing down longitudinal wave propagation
It is often described, that virtual photons are mere mathematical constructs, that can turn to real photons if there is enough time and space. And also, that virtual photons can mediate longitudinal ...
- 1
1
vote
3
answers
2k
views
Energy transfer with electromagnetic waves
As we know that the electrical energy is transferred via electromagnetic waves from the source to the load. My question is that, even if there is transfer of energy through the electromagnetic waves, ...
- 952
2
votes
2
answers
107
views
Propagation of electromagnetic waves
When EM waves propagate, they produce oscillating electric and magnetic fields. How did we know this? Is there any experimenting concluding this or it this just a theory?
- 67
1
vote
2
answers
827
views
Direction of propagation of electromagnetic waves
I have a differential equation for an electromagentic wave propogating in the z-direction and oriented alone the x-axis:
$$\frac{d^2 E_x}{d z^2}+\omega^2 \mu \epsilon E_x=0$$
and if I say $k^2= \omega^...
- 335
0
votes
2
answers
323
views
The role of the separation constant when solving the wave equation for electromagnetic waves & Cut off wave number
I have the following wave equation that I need help to solve via separation of variables:
$$\nabla^2 \mathbf{E} + k^2 \mathbf{E} = 0$$
Where E is the electric field and k is the wave number
Using ...
- 37