1. Physics 213 General Physics Lecture 8 0

2. 2 Last Meeting: Kirchhoff Rules, RC Circuit Today: Magnetism & Magnetic Field

3. 3

4. Magnetic Resonance Imaging (MRI)

5. Maglev Train

6. Magnetic Resonance Imaging (MRI) Imaging (MRI) Examples of Other Magnetic Field Applications

7. 7 Demo  Magnetic Materials, Magnets  Dip Meter  Attraction and Repulsion

8. 8

9. 9 Demo: iron filings

10. Magnetic Field Lines, sketch A compass can be used to show the direction of the magnetic field lines (a) A sketch of the magnetic field lines (b)

11. Magnetic Field Lines, Similar to Electric Dipole Magnetic DipoleElectric Dipole

12. 12

13. 13

14. 14

15. Earth’s Magnetic Field The Earth’s magnetic field resembles that achieved by burying a huge bar magnet deep in the Earth’s interior

16. A Few Typical B Values Conventional laboratory magnets 25000 G or 2.5 T Superconducting magnets 300000 G or 30 T Earth’s magnetic field 0.5 G or 5 x 10 -5 T

17. 17 Crookes Tube

18. 18

19. 19

20. Determining the Direction of Force, the Right Hand Rule Point your fingers in the direction of Curl the fingers in the direction of the magnetic field, Your thumb points in the direction of the force,, on a positive charge If the charge is negative, the force is opposite that determined by the right hand rule

21. . v -e-e B F F v -e-e B Right Hand Rule Examples Velocity out of page. Velocity into page.

22. 22

23. 23

24. 24 Q3

25. 25