The surface charge density of a thin spherical shell placed in an air medium is 88.54 c/m2 The intensity of the electric field measured 12 mm outside the shell from the centre of the shell is 5.625 × 1012 N/C. The thin spherical shell has a radius of:
1
10.5 mm
2
6.0 mm
3
0.35 mm
4
9.0 mm