All Questions
Tagged with electromagnetism experimental-physics
192
questions
58
votes
12
answers
15k
views
Home experiments to derive the speed of light?
Are there any experiments I can do to derive the speed of light with only common household tools?
- 6,000
18
votes
5
answers
4k
views
Home experiments using wireless LAN or mobile phones about electromagnetism?
Are there any nice experiments using wireless LAN access points or routers or mobile phones to demonstrate physical features of electromagnetic fields, especially em-waves?
More precisely I am ...
18
votes
3
answers
3k
views
How to experimentally reconstruct Maxwell's equations from scratch
What are the minimal experiments would one need to perform in order to reconstruct Maxwell's equations from scratch, assuming even the concepts of $\vec E$ and $\vec B$ are unknown?
While I'm not ...
- 11.5k
18
votes
5
answers
2k
views
Can we measure an electromagnetic field?
As far as I can check, the Aharonov-Bohm effect is not -- contrary to what is claimed in the historical paper -- a demonstration that the vector potential $A$ has an intrinsic existence in quantum ...
- 10.6k
15
votes
6
answers
30k
views
How do you determine power flow direction in a transmission line?
Below is a picture of a typical transmission line(about 200 kV). Is there a simple physics experiment which can be performed safely near the line, to determine the power flow direction. Or in other ...
- 2,697
14
votes
4
answers
4k
views
Kirchhoff's Voltage Law in a General Electromagnetic Field
Recently, Prof. Walter Lewin and YouTuber ElectroBOOM started a discussion about KVL, after Dr. Lewin claimed that KVL did not hold in the presence of an magneto-dynamic field. I would argue that Dr. ...
- 1,043
12
votes
1
answer
246
views
Weight of magnet depends on its N-S orientation?
I weighed a Neodymium disc magnet and found that it weighs about $1$ mg more when the north pole is upwards than when the south pole is upwards.
Can this be explained by "conventional" ...
- 5,925
11
votes
3
answers
6k
views
Experiment which shows that Newton's third law is not true for magnetic forces
I am just reading David Morins "Introduction to Classical Mechanics". He writes about Newtons third law the following:
It holds for forces of the “pushing” and “pulling” type, but it fails
for ...
- 1,702
11
votes
1
answer
994
views
How the inverse square law in electrodynamics is related to photon mass?
I have read somewhere that one of the tests of the inverse square law is to assume nonzero mass for photon and then, by finding a maximum limit for it , determine a maximum possible error in $\frac{1}...
- 728
8
votes
3
answers
3k
views
The physics behind a homemade particle accelerator
I have made a particle accelerator, like the one in the following image.
homemade particle accelerator
When a metallic pellet passes through the coil, it lights up and generates a magnetic field ...
8
votes
5
answers
3k
views
How do they find the energy of a photon?
Is the actual energy of a photon ever measured? How is it done?
I read that a photon is usually identified by diffraction, that means its wavelength is measured, is that right? In this way we ...
user104372
8
votes
2
answers
1k
views
What empirical evidence is there for displacement current?
I wonder what more or less direct measurements of the displacement current exist. I know that the existence of em waves demonstrates its existence, though somewhat indirectly. I also know that there ...
- 3,138
7
votes
2
answers
964
views
Evidence for electrodynamics in curved spacetime
Field theories in curved spacetime is usually formulated by integrating their Lagrangian over the curved spacetime. For example, for electrodynamics, we have the action
$$ S = \int d^4x \left( -\frac{...
- 517
6
votes
1
answer
18k
views
How does the speed of a DC motor depend on the size of the coil?
I have to build a simple electric motor by attaching a magnet to a battery, extending the terminals of the battery (with stiff wires so they could act as supports), and placing a coil of wire on top ...
- 2,889
6
votes
1
answer
350
views
Experimentally finding units of physical quantity?
Say you had a new physical quantity you wanted to determine the units for. How do you go about this?
For the strength of an electromagnet for example, you could carry out a simple experiment like the ...
- 1,241