Electric Field in a Conductor

📌 CONCEPT: When a charged object is brought near a conductor, the free electrons in the conductor move to the surface to neutralize the effect of the external charge, resulting in zero electric field inside the conductor.

📐 RULE / FORMULA: According to the concept of electrostatic equilibrium, the electric field inside a conductor is always zero.

💡 WORKED EXAMPLE: Given a spherical conductor of radius R with a point charge q at its center, and a second point charge -2q brought near the conductor. Since the charge q is already at the center of the conductor, the charge will redistribute itself to the surface to maintain electrostatic equilibrium. The electric field inside the conductor will remain zero.

⚠️ COMMON MISTAKE: Students often forget to consider the redistribution of charge on the conductor when an external charge is brought near, leading to incorrect assumptions about the electric field inside the conductor.