A2L Item 204

Goal: Hone the concept of a conductor

Source: 283-225, Charge induced in a neutral conductor

A positive charge +Q is placed outside a neutral conductor. Inside the
conductor is a cavity containing no charge. What is the net charge on
the surface bounding the cavity?

  1. A positive charge +Q
  2. A positive charge +q < +Q
  3. Zero charge
  4. A negative charge |-q| < |+Q|
  5. A negative charge -Q
  6. Cannot determine the charge.

Commentary:

Answer

(3) Students have difficulty envisioning induced charge distributions,
especially when the conductor has an irregular shape.