1. Physics for Scientists and Engineers II, Summer Semester 2009 1 Lecture 13: June 19 th 2009 Physics for Scientists and Engineers II

2. Physics for Scientists and Engineers II, Summer Semester 2009 2 Ampere’s Law Top View

3. Physics for Scientists and Engineers II, Summer Semester 2009 3 Ampere’s Law Top View

4. Physics for Scientists and Engineers II, Summer Semester 2009 4 Ampere’s Law

5. Physics for Scientists and Engineers II, Summer Semester 2009 5 Ampere’s Law Top View

6. Physics for Scientists and Engineers II, Summer Semester 2009 6 Ampere’s Law

7. Physics for Scientists and Engineers II, Summer Semester 2009 7 Example Application of Ampere’s Law I2I2 I1I1

8. Physics for Scientists and Engineers II, Summer Semester 2009 8 Example Application of Ampere’s Law

9. Physics for Scientists and Engineers II, Summer Semester 2009 9 Preventing Pitfalls

10. Physics for Scientists and Engineers II, Summer Semester 2009 10 Preventing Pitfalls

11. Physics for Scientists and Engineers II, Summer Semester 2009 11 A Long Solenoid (Wire wound in the form of a helix)

12. Physics for Scientists and Engineers II, Summer Semester 2009 12 A Long Solenoid (Wire wound in the form of a helix)

13. Physics for Scientists and Engineers II, Summer Semester 2009 13 Problem 33 in the book x z

14. Physics for Scientists and Engineers II, Summer Semester 2009 14 Problem 33 in the book x z

15. Physics for Scientists and Engineers II, Summer Semester 2009 15 Gauss’s Law in Magnetism

16. Physics for Scientists and Engineers II, Summer Semester 2009 16 Gauss’s Law Comparison Electric flux through closed surface is proportional to the amount of electric charge inside (electric monopoles). Isolated magnetic monopoles have never been found.

17. Physics for Scientists and Engineers II, Summer Semester 2009 17 Magnetism in Matter We now know how to build “electromagnets” (using electric current through a wire). We also found that a simple current loop produces a magnetic field / has a magnetic dipole moment. How about the “current” produced by an electron running around a nucleus? Let’s use a classical model (electron is a point charge orbiting around a positively charged nucleus. - + direction of motion of electron The tiny current loop produces a magnetic moment Orbital angular momentum of electron

18. Physics for Scientists and Engineers II, Summer Semester 2009 18 Magnetism in Matter - + L = “orbital angular momentum”

19. Physics for Scientists and Engineers II, Summer Semester 2009 19 Quantization

20. Physics for Scientists and Engineers II, Summer Semester 2009 20 Spin