ECE 305 Electromagnetic Theory Fall 2016 ECE 305 Electromagnetic Theory Lecture 4: Chapter 4 Electrostatic Fields Part 3 (§4.7, 8, 9 and 10) Qiliang Li Dept. of Electrical and Computer Engineering, George Mason University, Fairfax, VA

§4.7 Electric Potential Suppose we move a point charge Q from A to B in an electric field E Force: F = Q E Work is done to displace the charge Q by dl potential difference b/w A and B

§4.7 For example:

For different situations: (C is constant determined by reference point )

example 4.10 example 4.11

example 4.11 solution Find ρ, r and C

§4.8 Relationship between E and V – Maxwell’s Equation The potential difference between A and B is independent of path taken: For an enclosed path L

§4.9 An Electric Dipole and Flux Lines

§4.10 Energy Density in Electrostatic Fields

For continuous charge