# An electricity and magnetism problem by Jaswinder Singh

**Electricity and Magnetism**Level 3

A system consists of a uniformly charged sphere
of radius **R** and a surrounding medium filled by
a charge with the volume density \[\large\rho =\frac { A }{ r }\]
, where
**"A"** is a positive constant and **"r"** is the distance
from the center of the sphere. Find the charge of
the sphere for which the electric field intensity
E outside the sphere is independent of R.