{"knowledge_schema": {"broad_category": "Physics \u2192 Electrostatics \u2192 Electric Fields", "refinement": "This problem involves understanding the behavior of electric fields in the presence of conductors and charges, particularly focusing on the effects of a charge placed within a cavity of a conductor.", "specific_scope": "The scenario describes a spherical conductor with a cavity containing a charge, and the task is to determine the electric field at a point outside the conductor, taking into account the geometry of the system.", "goal": "Calculate the electric field at point P outside the spherical conductor due to the charge placed inside the cavity."}, "summary": "In this problem, we analyze the electric field generated by a charge placed inside a cavity of an uncharged spherical conductor. According to electrostatic principles, the electric field outside a conductor is influenced only by the net charge enclosed within it. Since the conductor is uncharged and the charge +q is placed inside the cavity, the electric field at a point outside the conductor can be determined using the geometry of the system. The correct expression for the electric field at point P, considering the distances and angles involved, must be derived from the principles of electrostatics."}