# Shape of electromagnetic field

hello

what are the shapes that a magnetic (of electromagnetic origin, so that it will be able to vary in intensity and switch on/off controlled by electricity) can have?

for example, can we create an electromagnetic in the shape of a cylinder of specific dimensions? ie. to produce an electromagnetic field that will only be present and act in the limits of a given dimension cylinder?

thanks!

## Answers and Replies

Just plug the solution that you are interested in into the Maxwell PDE and see if inconsistecy arise. Have fun.

Vanadium 50
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A field has a value - possibly zero - at every point in space. It doesn't have a shape.

It is possible to confine a field to a space, but it requires materials. For example, the field inside a parallel plate capacitor is non-zero, but outside it is zero. If you rolled it up into a cylindrical shape, the field would be zero everywhere outside and would have regions of non-zero value on the inside.

Just plug the solution that you are interested in into the Maxwell PDE and see if inconsistecy arise. Have fun.

what is Maxwell PDE? you throw a term with some initials and you expect us to know it

I'm sorry....my fault. Not so much time ago a guy called Maxwell performed experiments on the electromagnetic fields, and with the data from the experiments and some logic he "invented" the mathematical rules that electromagnetic fields follow. These are not simple algebraic equations but equations involving the various E(x,y,z,t) and B(x,y,z,t) functions and theirs partial derivatives. This kind of equations are called Partial Differential Equations. If an electromagnetic fields exist you can be certain that it is a solution of the infinite solutions of the Maxwell PDE.

I'm sorry....my fault. Not so much time ago a guy called Maxwell performed experiments on the electromagnetic fields, and with the data from the experiments and some logic he "invented" the mathematical rules that electromagnetic fields follow. These are not simple algebraic equations but equations involving the various E(x,y,z,t) and B(x,y,z,t) functions and theirs partial derivatives. This kind of equations are called Partial Differential Equations. If an electromagnetic fields exist you can be certain that it is a solution of the infinite solutions of the Maxwell PDE.

that's cool of him
is there an online tool to experiment with the various solutions of these equations? to generate visual representations of electromagnetic fields?

:) solving those PDE is very difficult...there are some numerical techniques (it means that they are not solved "mathematically" so to speak), there are some VERY expansive programs like CST that help scientists visualize and study EM fields...i sincerely do not know if there is something on the web for some specific case...maybe try to look at the Wolfram site! there are some demos probably