1. Physics for Scientists and Engineers II, Summer Semester 2009 1 Lecture 11: June 15 th 2009 Physics for Scientists and Engineers II

2. Physics for Scientists and Engineers II, Summer Semester 2009 2 Force on a Charged Particle in a Magnetic Field

3. Physics for Scientists and Engineers II, Summer Semester 2009 3 Force on a Positive Charge

4. Physics for Scientists and Engineers II, Summer Semester 2009 4 Force on a Negative Charge

5. Physics for Scientists and Engineers II, Summer Semester 2009 5 Units of Magnetic Field

6. Physics for Scientists and Engineers II, Summer Semester 2009 6 Motion of a Charged Particle in a Uniform Magnetic Field Convention: Magnetic field vector points into the page Magnetic field vector points out of the page +q

7. Physics for Scientists and Engineers II, Summer Semester 2009 7 Motion of a Charged Particle in a Uniform Magnetic Field +q

8. Physics for Scientists and Engineers II, Summer Semester 2009 8 Motion of a Charged Particle in a Uniform Magnetic Field

9. Physics for Scientists and Engineers II, Summer Semester 2009 9 Uniform Magnetic Field Plus Electric Field +q E The charge will pass through this crossed magnetic and electric field In a straight line under the following condition:  Velocity selector +q

10. Physics for Scientists and Engineers II, Summer Semester 2009 10 The Mass Spectrometer Principle q Detector array

11. Physics for Scientists and Engineers II, Summer Semester 2009 11 Magnetic Force Acting on a Straight Piece of Current-Carrying Conductor A q + L

12. Physics for Scientists and Engineers II, Summer Semester 2009 12 …Small Segment of Current-Carrying Conductor

13. Physics for Scientists and Engineers II, Summer Semester 2009 13 Example (a variation on Example 29.4 – different direction of B) x y What is the net force on this loop?

14. Physics for Scientists and Engineers II, Summer Semester 2009 14 Net force on the straight section x y

15. Physics for Scientists and Engineers II, Summer Semester 2009 15 Force on the semicircle x y

16. Physics for Scientists and Engineers II, Summer Semester 2009 16 Total Force

17. Physics for Scientists and Engineers II, Summer Semester 2009 17 Torque on a Current Loop in a Uniform Magnetic Field 1 2 3 4 The forces on sections 1 and 3 are equal and opposite. Similarly, the forces on 2 and 4 are equal and opposite. Bottom view: 24

18. Physics for Scientists and Engineers II, Summer Semester 2009 18 …and rotated by 90 degrees…. Bottom view: 2 4

19. Physics for Scientists and Engineers II, Summer Semester 2009 19 …at some arbitrary angle

20. Physics for Scientists and Engineers II, Summer Semester 2009 20 Right hand rule to determine direction of A

21. Physics for Scientists and Engineers II, Summer Semester 2009 21 Magnetic Dipole Moment of the Loop

22. Physics for Scientists and Engineers II, Summer Semester 2009 22 Magnetic Dipole Moment of the Loop