There are three concentric thin spheres of radius `a,b,c (agtbgtc)`. The total surface charge
Channel: Doubtnut
Date: 2020-01-19

There are three concentric thin spheres of radius `a,b,c (agtbgtc)`. The total surface charge densities on their surfaces are `sigma,-sigma,sigma` respectively. The magnitude of the electric field at `r` (distance from centre) such that `agtrgtb` is: