# Torque on a disk with charge

Imagine you have a disk with some number of charged metallic spheres spaced equally around a disk at some distance from the center of the disk and those spheres are mechanically attached to the disk. And if you have a changing magnetic field pass through through the center of the disk in a direction normal to the surface of the disk, there is a torque that is applied to the disk.

For the sake of simplifying a problem,

• can you instead imagine a uniformly charged line (whose total charge is equal to that of all the spheres) at the same distance from the center of the disk without changing the value of the torque applied to the disk?

I do not believe the two systems would result in a different torque as you could imagine the entire charge is located at a point at the center of each of the spheres and I do not believe there would be a difference in torque between a discrete and a continuous charge distribution of the same charge as long as it is the same distance from the center.