What is the size of the magnetic dipole moment?

Member has been warned not to remove the template.
Consider the magnetic field B generated by a magnetic dipole. The intensity of B measured along the
axis of the dipole, at a distance of 10 cm from the dipole itself, is 1.0 10-5 T. What is the size of the
magnetic dipole moment? (μ0 =4π10-7 mkg/C2)
a) 0.050 Am2
b) 5 10 -4 Am2
c) 0,1 Am2
d) 1 10 -4 Am2

I know that the magnetic dipole moment involves the area ( in fact its unit is A* m^2). But the problem does not provide the area of the loop (?).

So I know the intensity of the field, how do I get the dipole moment?

So, which formula do I have to use? I don't understand the quantities involved in the formulas you reffered to

Homework Helper
Gold Member
So, which formula do I have to use? I don't understand the quantities involved in the formulas you reffered to
## \vec{m}=IA \, \hat{z} ## is the magnetic dipole. Along the axis (at least for positive z) will mean that ## \vec{m} \cdot \vec{r} =m r ## and ## \vec{r}=r \hat{z} ##. That should make it easy to evaluate the numerator of ## B ##.

Last edited:
berkeman
I still have a question. I don't know if it's correct to ask this. I think we didn't see this formula in the course. So is there another way to find the magnetic dipole moment?
Maybe with a parallelism with electric dipole moment.