(1) After the inner and outer balls are connected by wires, all the net charges will be distributed on the surface of the outer spherical shell, so the potential of the two spherical shells can be determined by the total power carried by the system (and of course the radius of the outer spherical shell). In this way, the electric field inside the outer spherical shell (including the inner spherical shell and other internal spaces) is all zero, while the electric field outside the outer spherical shell is equivalent to the electric field generated by the charge at the center of the sphere in Gauss theorem. If the electric quantity Q of the inner ball is set when the wires are not connected, the electric field distribution can be easily obtained by using Gauss theorem, and then the electric potential of the inner ball is expressed by Q, which is equal to the known quantity of 270V V, then the initial electric quantity Q of the inner ball and the total electric quantity Q of the system can be obtained. Given the radius of the outer sphere, the electric field distribution outside the outer sphere can be easily obtained by using Gauss theorem, that is, the potential of the outer sphere after two spheres are connected by wires.

(2) If the inner spherical shell is grounded, the potential of the inner spherical shell will become zero, that is, its potential is equal to the potential at infinity from the system. Similar to (1), the charge quantity q' of the inner spherical shell can still be set after grounding, and the electric field distribution of the system can be obtained by Gauss theorem, and then the potential of the inner spherical shell represented by q' can be equal to 0, which is the charge quantity of the inner spherical shell after grounding. The potential of the outer sphere is also determined by the total power q' of the system at this time.