Question

a charged sphere is rotating with w find magnatic field at cebter

Answer 1

The magnetic field at the center can be found using the formula derived from considering the rotating sphere as a collection of current loops. The exact formula depends on the charge distribution within the sphere (uniform or non-uniform). Without further information, a general expression cannot be provided.

Answer 2

To find the magnetic field at the center of a rotating charged sphere, one would typically integrate the contributions from infinitesimal current loops formed by the rotating charges. The angular velocity $\omega$ and the charge density are crucial parameters. The final expression will depend on whether the charge is uniformly distributed or not. A more detailed solution would require specifying the charge distribution.