2
votes
0answers
59 views

Odd experiment results (electromagnetics)

Okay, a bit of background. So I'm working on a linear accelerator (you might know it as a Gauss rifle), and I had worked through the equations I thought I needed (Magnetic force, displacement, etc.) ...
0
votes
0answers
16 views

How big can be gradient of magnetic induction (in lab)

I'm thinking about magnetic levitation and how big force can push a diamagnetic when we put it in inhomogenious magnetic field. As far as I know, force exerted on a diamagnetic is proportionald to ...
6
votes
2answers
106 views

Experiment which shows that Newtons 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
vote
1answer
15 views

The strength and control over the strength of electromagnets, correlation between the strength and weight of the magnets

I am currently working on a project that aims to use the attraction & repulsion between two electromagnets as an alternative to weights, from a physiotherapy and rehabilitation perspective to help ...
2
votes
1answer
28 views

Thermal emission cathode electron velocity distribution

I can't find any experimental data (or theoretical expression) on what is the velocity (or energy) distribution of thermal emission cathode electrons emmited from the cathode at approximately 2000 K ...
0
votes
0answers
19 views

Strength of Magnet in Magnetic Bearings

While reading about magnetic bearings, one reads about passive/active magnetic bearings. By passive, one means no electric current is put into the bearing for attaining magnetic levitation/flux. In ...
1
vote
2answers
218 views

Has magnetism been experimentally demonstrated at the quantum level?

I've learned that magnetic fields are generated by electric currents, and that electric current is the motion of electrons and stuff like that. Many textbooks also talk about "point charges" and have ...
1
vote
1answer
30 views

What is the easiest way to demonstrate low magnetic flux NMR on the bench?

I'm trying to build my own low fux density bench NMR set-up, and am well-versed in electronics. Continuous Wave is supposed to be the easiest. I see commercial instruments that stimulate elements in ...
2
votes
1answer
50 views

Magnet spinning between two other magnets

Suppose, we have two magnets, MA, MB, and we have a third magnet MC in between the two magnets. Each magnets' north pole faces the other magnets south pole, and the magnets are placed horizontally ...
0
votes
2answers
92 views

Inductor Charging and Discharging

Why does the inductor discharges in the same path ( same direction of current ) as that of its charging unlike a capacitor which discharges in the direction opposite to its charging(current direction ...
0
votes
1answer
86 views

Circuit breaker Trips during thunderstorm

The circuit breaker at the electrical mains trips at home when there is a thunderstorm outside. Why does this occur?
1
vote
2answers
99 views

Experiments which show the phenomenon of closed electric field lines

In german physics introductory texts often the following experiment is cited which "shows" that a changing magnetic field can induce an electric field with has closed field lines. Here is a picture of ...
1
vote
0answers
26 views

How to isolate and verify the source of optical absorption/effects?

This is similar to my other question, but not the same -- that one was about the energy ranges of various absorption mechanisms, and this one is more about experimental techniques to find them. Let's ...
3
votes
1answer
295 views

Why my simple electromagnetic experiment does not work?

I make a setup (see attached picture). ONE coil (1" diameter x ~120 turns), which is separated with a gap, is mount on two sides. Each side has an iron rod (1" diameter x 6" long) to increase the ...
0
votes
1answer
53 views

Maximum magnetic strength achievable

What will be the maximum magnetic strength to which a piece of ferromagnetic substance can be magnetised? What will the maximum strength possible for a piece of iron? How would the shape of the ...
1
vote
0answers
73 views

Different phase in capacitively coupled RLC circuits

I was trying to work with some data for a lab report I'm writing about capacitively coupled RLC circuits. The setup is pretty simple and looks like that: Where $C^{'}$ is the coupling capacitance. ...
2
votes
1answer
89 views

Waveguides Transmission Mode Determination

How do I know if I have TE, TM, or TEM rectangular conductive waveguide? For instance, I am doing a lab where we want maximum magnetic field in the waveguide, does that mean we want the TE because ...
0
votes
1answer
83 views

Issue with running a Van De Graaff generator

I am following this online video: http://www.youtube.com/watch?v=fsT69XnjxgU but my Van De Graaff generator is not working. I am using pvc pipes for the body, nylon and electrical tape as two rollers, ...
1
vote
2answers
230 views

Oil drop experiment and quantization of charge

How to systematically show that the resulting charges in oil drop experiment are integers multiplied by $e$ in other word how to extract $e$ from the data?
0
votes
1answer
72 views

How magnets create electricity in conductors?

what are the reasons for current appearing in a wire when wire is in a changing magnetic field?
3
votes
1answer
99 views

Motion in a Paul trap: $2n$th harmonic with larger amplitude than $n$th harmonic

Using a Paul trap, we captured the motion of a light charged particle (based on a rotating potential applied by AC current). Our rotational frequency was 50 Hz, and so when used FFT on the data, we ...
1
vote
0answers
55 views

Long range repulsion in anomalous solids

As far as I know things like rocks, walls, rubber balls, polished tables etc. exert a short range repulsive force on other everyday objects that is responsible for hardness, softness, collisions, ...
4
votes
1answer
151 views

Experiments looking for monopoles

Background: (skip it if you know it) In the easiest formulation of classical electromagnetism magnetic monopoles do not exist. In fact, the Maxwell's equation $\nabla \cdot \vec{B}=0$ implies (using ...
3
votes
2answers
362 views

Electromagnetic Momentum

My book says : The fact that electromagnetic radiation of energy carried momentum was known from classical theory and from the experiments of Nichols and Hull in 1903. This relation is also consistent ...
4
votes
1answer
350 views

Fourier transformation, electric field and magnetic field to have a shielding lattice against particles

With Fourier-Series Expansion, we can write a function as sum of many non-repating different frequncied different amplituded sine and cosine functions. Lets assume we know electric-field and ...
1
vote
0answers
863 views

Calculation of magnetic force magnitude from a parmenant magnet

I was wondering how strong a magnet should be in order to be able to horizontally attract 0.2 Kg of pure iron at a distance of 0.3 M. Since I know nothing about magnets, I started looking for ...
1
vote
0answers
204 views

Easy question about magnetism?

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 ...
10
votes
1answer
374 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 ...
0
votes
1answer
650 views

measuring electromagnetic induction

There is a famous law which says that a potential difference is produced across a conductor when it is exposed to a varying MF. But, how do you measure it to prove? It is quite practical. ...
4
votes
2answers
938 views

First experiment which was used to prove existence of Electromagnetic waves

When I was in high school I heard from my physics teacher in the last year of high school when he was starting the chapter of electromagnetic waves that the first person who proved existence of ...
3
votes
4answers
771 views

Magnetic fields and gravitational waves. How far do they reach?

I read that magnetic fields perpendicular to a current shoot out and expand all the way to infinity. Additionally a gravitational wave, no matter how small will also expand to infinity at the velocity ...
2
votes
1answer
63 views

Can a SQUID perform real time measurements of a slow varying magnetic flux?

It is well known that a SQUID can detect an extremely small magnetic flux. What if the flux is time-dependent? E.g. a slow varying sinusoidal magnetic flux $$\Phi=\Phi_0\sin(\omega t).$$ Can I ...
2
votes
1answer
99 views

What is the reason behind the shape of the absorption curve of electron paramagnetic resonance

In our EPR experiment, the signal looks like the "first derivative" part of the above picture. Why is this? What does the "first derivative" mean and why is it the quantity our instruments detect in ...
2
votes
0answers
272 views

Levitation rotation speed involving laser acceleration, pyrolytic graphite and a vacuum

The experment would involve a small NIB magnet levitating between or on the diamagnetic material pyrolytic graphite, unlike other forms of levitation this doesn't require power to run such as ...
1
vote
0answers
84 views

How to set the electric potential on a certain boundary to a certain value experimentally?

In electrostatic boundary value problems, usually the potential is set to some function or a constant on a certain boundary. It is never taught or told in textbooks how such assignment might be ...
9
votes
3answers
7k 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 ...
3
votes
1answer
574 views

Measuring the vacuum permittivity

So I was reading the EF experiment that's used at the MIT to measure the vacuum permittivity and I was thinking about trying it just to see how it works: ...
3
votes
1answer
243 views

PNMR, Pulsed Nuclear Magnetic Resonance, Experiment

I am writing a lab report for class on PNMR experiment that we did. How come in this experiment we don't worry about the electron spins in our sample? Aren't the electrons affected by the PNMR machine ...
16
votes
5answers
2k 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 ...
36
votes
13answers
9k 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?