A point charge Q is placed inside a cavity within a solid isolated conducting sphere. Consider points A, B and C as shown in the figure, where the magnitudes of the electric fields are E_A , E_B and E_C , respectively. The points B and C are at the same distance from the center of the solid sphere. The correct option is :

Step-by-step solution

Point A is located inside the cavity where a point charge Q is present. The electric field inside the cavity is the superposition of the field due to the charge Q and the induced charge on the inner surface of the cavity. This resultant field is non-zero, so E_A 0 . The point charge Q inside the cavity induces a charge -Q on the inner surface of the cavity and a charge +Q on the outer surface of the isolated conducting sphere. Because the outer surface of the sphere is perfectly spherical and there are no external