Question

(figure 1) a spherical cavity is hollowed out of the interior of a neutral conducting sphere. at the center of the cavity is a point charge, of positive charge q.
part g
the electric field within the cavity, ( e_{\text{cav}} ):

• would change
• would not change

part h
the electric field outside the conductor, ( e_{\text{ext}} ):

• would change
• would not change

Explanation:

Part G

The electric field within the cavity of a neutral conducting sphere with a point charge at the cavity's center is determined by the point charge alone (Gauss's law, and the conductor's charges redistribute to cancel field inside the conductor, not the cavity). So, if conditions (like the charge at center, symmetry) remain, \( E_{\text{cav}} \) doesn't change.

For the electric field outside the conductor, the conductor (with induced charges) acts as a spherical charge distribution (equivalent to the central charge due to symmetry). So, external field depends on the net charge (here, the central \( +q \) as the conductor is neutral, and induced charges don't affect external field). Thus, \( E_{\text{ext}} \) would not change.

Answer:

would not change

Part H