1. AP Physics L17_Maxwell The basis of E&M
Maxwell’s Equations
The basis of E&M

2. Displacement current Kirchoff’s junction rule: I = 0
What does this mean in a charging capacitor? I ?
current out?
current in?

3. Amperean loop surfaces
What is enclosed current?

4. Amperean loop surfaces
dFE dt
Displacement current iD =

5. Displacement current is real
creates a B field just like any other I

6. Beautiful symmetry
A changing magnetic field produces an electric field.
A changing electric field produces a magnetic field.

7. Maxwell’s equations  EdA =  BdA = 0  Bdl = m0Iencl  Edl =
Gauss’s law, E
Qencl
 EdA =
 BdA = 0
Gauss’s law, B
 Bdl = m0Iencl
Ampere’s law
Faraday’s law
dFB dt
 Edl =

8. Free Space  EdA = 0  BdA = 0 No charge or conduction current
Gauss’s law, E
 EdA = 0
 BdA = 0
Gauss’s law, B

9. Free Space  Bdl = m0 EdA  Edl = BdA
No charge or conduction current
Ampere’s law
dFE dt
 Bdl = m0
EdA d
= m0
Faraday’s law
dFB dt
 Edl = d
BdA =