# Tagged Questions

The magnetic-fields tag has no wiki summary.

1answer
52 views

### What geological properties of the earth could we deduce by measuring magnetic field strength and direction?

I wonder if it is of any use for a geophysicist, if we measure the magnetic field strength and direction of the earth. Could we make valid statements about the composition of the the earth, earth ...
1answer
186 views

### If the Moon had gravity as good as the Earth and a magnetic field could it have supported life?

If the Moon had gravity as good as Earth and a magnetic field could it have supported life? Because if the Moon had gravity, it could have retained water more than is present today on the surface. ...
0answers
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### Is there an equation for the magnetic field of a conductor attached to a magnet?

Let's say I have a hollow conductive rod, 10mm diameter (O.D.), and I place a magnet of known strength 50mm up the shaft. What is the microTesla (mT) or Gauss (G) of the magnetic field (or flux ...
0answers
60 views

### Would an aluminum cup placed around the back and sides of a disc magnet increase the field strength at the front?

I have read that certain materials, specifically ones with distinct magnetic properties, can influence the way magnetic field behaves around a magnet. If you were to place a disc magnet inside an ...
1answer
122 views

### How to calculate the effect of the earth's magnetic field on a HZE particle?

I'm trying to calculate the protection provided by the earth's magnetic field from HZE particles to astronauts in low earth orbit, such as those on the ISS. HZE particles are often quoted as a danger ...
1answer
107 views

### Linear dependence of magnetic potential on current density

I'm a mathematician learning physics to provide some background for my mathematical work (especially pde's!). I have been reading through Jackson's Classical Electrodynamics (3rd edition), and I was ...
1answer
56 views

### Is it possible to determine astronomically/astrophysically whether other planets have ever encountered polarity reversal?

We know of geomagnetic flip in Earth's history by studying geologic data. Given other planets in the system also possess a magnetic field leads to the assumption that such polarity reversal may not be ...
1answer
409 views

### Magnetic poles in Halbach array?

I am a bit confused by the description of Halbach arrays. It is said that the line of magnets aligned in certain way results in cancellation of magnetic field on one side of the array, and ...
1answer
288 views

### Physical meaning of magnetic length

What is the physical meaning of magnetic length $\ell_B=\frac{\hbar c}{e B}$ in 2D electron system under magnetic field? When $\ell_B \longrightarrow a$, where $a$ is the lattice constant, does that ...
1answer
131 views

### Point where resulting magnetic field is equal to 0

I am trying to solve the following task Given 3 infinitely long current carrying wires, as shown on image ($I_1=I_2$ , $I_3=2I_1$) and $r=5 cm$ calculate the point between them (in the same plane; ...
1answer
88 views

### How does a magnet work?

I'm having trouble understanding how a magnet (not the field that is generated as a result but the material itself) work. The particles are aligned in a specific direction to give rise to force but I ...
0answers
68 views

### Changing the charging properties of an inductive charging coil

I am attempting to modify an existing inductive charging coil (Palm Touchstone) so that it outputs the correct magnetic flux for a different wireless charging standard (Qi). I am doing this as an ...
2answers
118 views

### Force on a bar magnet

A bar magnet is freely falling vertically inside a conducting ring placed in horizontal plane. Will it fall with an acceleration equal to g, less than g or greater than g?
1answer
117 views

### (Earth's) magnetic field

Always when we want to represent the magnetic field of the earth we see a similar image: My question is, what exactly does this show? What are the blue and orange lines, what do they represent? Why ...
0answers
84 views

### Angle of Inclination

How do I calculate the angle of Inclination for a specific location on the Earth? The only Information I've got is the longitude and latitude in degree, so I do not understand. I now ...
1answer
237 views

### Mutual Inductance and the Dot Convention

Can anyone please explain me, the dot convention in coil systems (Mutual and self inductance) with some related images to understand..?
2answers
2k views

### Why does electricity flowing through a copper coil generate a magnetic field?

Can some one please explain to me why electricity flowing though a copper coil generates a magnetic field or where I could possibly find that information? Are there other materials that produce a ...
4answers
2k views

### Earth's Magnetic Field, Human Brain and Sleep

I remember reading somewhere: when you sleep in a way subjecting your body to cut the geomagnetic field at right angles, you become highly emotional whereas when it is Parallel, it cools your ...
1answer
71 views

### Does a celestial system exhibit a collective magnetic field?

Sol exhibits a magnetic field, most of the planets in orbit around Sol exhibit a magnetic field - strong and weak both. Does the solar system as a whole exhibit a magnetic field? Does the paradigm ...
2answers
403 views

### Mechanism by which electric and magnetic fields interrelate

I read that force due to electric field on some particle in one reference frame can exhibit itself as force due to magnetic field in some other reference frame and that electric and magnetic fields ...
1answer
109 views

### Separation of solids from liquids using magnetic waves

Using magnetic forces, I want to separate solids from liquids in a solution as a centrifuge would do. Is there a way to hit a volume of liquid and get it to separate liquids and solids with heavy ...
3answers
664 views

### How to make a small tokamak?

$\require{mhchem}$I made a fusor once, like the easy science project: deuterium-deuterium ones, but they're really inefficient. I was wondering if it would be possible to make a small tokamak; not one ...
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