1. The problem statement, all variables and given/known data Two concentric spherical shells carrying uniformly distributed charges +Q and -Q at radii a and b, respectively (b>a). Now, they are immersed in a uniform magnetic field pointing along the z-axis. Find the angular momentum of the fields. 2. Relevant equations No need. (I know them; don't need help using them; I can post them if somebody really wants). 3. The attempt at a solution I understand the math and the equations that must be used. I simply need to find the E and B fields. I am confused as to what happens when placing the spheres in the uniform magnetic field. I know that typically for a spherical capacitor, the only non-zero charge will be a < r < b. I don't believe this will change when placed in the uniform magnetic field, and I think the E field will remain as E=k*Q/r^2 pointing radially outward. However, what will the B-field be within the spherical capacitor? It doesn't seem likely that it would remain the same (in the z-direction); but I am not sure how it would change. Also, since E is zero at r<a and r>b, I don't need to worry about the B-field in those locations to calculate the angular momentum of the fields/ My confusion is simply on the physical principles. Can somebody help clear up what is happening for the fields at a<r<b? If any of my understanding above is incorrect, please let me know that as well. I appreciate any attempt to help (and apologize if this is the wrong section).