Electric Charges and Conductors: Shielding and Electric Fields, Slides of Electrical Engineering

Download Electric Charges and Conductors: Shielding and Electric Fields and more Slides Electrical Engineering in PDF only on Docsity! 1/23/12 1 1/23/12 1 From Lecture #1: Conductors versus Insulators •  Insulators: material in which electric charges are “frozen” in place. •  Conductors: material in which electric charges can move around “freely. 1/23/12 2 Conductors If an excess charge is placed on an isolated conductor, that amount of charge will move entirely to the surface of the conductor. None of the excess charge will be found within the body of the conductor. 1/23/12 3 Conductors Isolator Conductor with a Cavity 1/23/12 4 Conductors: Shielding from an Electrical Field •  Electric field lines for an oppositely charged metal cylinder and metal plate. Note that: 1.  Electric field lines are perpendicular to the conductors. 2.  There are no electric field lines inside the cylinder. 1/23/12 2 1/23/12 5 Conductors: Shielding from an Electrical Field student sensor screened cage sparks Van de Graaff generator 1/23/12 6 Conductors: External Electric Field 1/23/12 7 Planar Symmetry: Infinite Sheet of Charge Non-Conducting Sheet + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +" 1/23/12 8 Example: Two Parallel Non-Conducting Sheets +" " In this example, assume + > " + + + + + + - - - - - - + + + + + + - - - - - - Find the electric field to the left of the sheets, between the sheets and to the right of the sheets."