# Magnetic monopole

1. Nov 5, 2005

### Feynmanfan

I need to find out at what distance creates a magnetic monopole the same magnetic field as an electron with Bohr's magnetron magnetic momentum.

I don't know how to calculate the field of a monopole. I know what an electric charge is; but a monopole? As a clue I've been given Dirac's condition between e charge and the "monopole" magnitude.

2. Nov 6, 2005

### lightgrav

I expect you're supposed to find the distance BETWEEN two monopoles
(ie, making a dipole) that essentially re-creates the field of an electron.

The field strength of a single monopole decreases as 1/r^2,
while the field of an actual electron decreases as 1/r^3 (like a dipole).

3. Nov 6, 2005

### elhinnaw

Im not quite sure what your question is, but if this is the correct interpretation:

"at what distance will a magnetic monopole create the same magnetic field as an electron with Bohr's magnetron magnetic momentum?"

In magnetostatics if there was a magnetic monopole, the field would be:

B = (m0/4pi)*(qm/r^2)er

I worry for you because I have done a problem where I was supposed to calculate the angular momentum stored in the 2 fields caused by an electric charge and magnetic monopole seperated by a distance D, and the answer was quite shocking.

4. Nov 7, 2005

### dextercioby

What is an electric monopole ?? Assume it is stationary (it doesn't move). How do you compute its field (the electrostatic field it generates). Then mirror all calculations for the case of a magnetic monopole.

Daniel.