2. Refresher  Basic concept Like poles will repel Unlike poles will attract

3. Refresher  When a current is passed through a conductor, a magnetic field is produced Right hand grip

4. Definitions  Conductor A substance, body, or system that conducts electricity  Magnetic field A field of force surrounding a permanent magnet or a moving charged particle

5.  When a movable current carrying wire is placed in a magnetic field it will experience a force and the wire will move/ jump out of the field. This is known as the motor effect

6. Charged particles  A charged particle moving Parallel to magnetic field ○ Not much effect Perpendicular to magnetic field ○ Experiences sideways force that is proportional to the strength of the magnetic field ○ Known as the Lorentz force

7. Lorentz force  The proton is constantly deflected Moving in circular motion

8. F = BIl F = force produced (N) B = Flux density (T) I = current (A) l = length of wire in field (m) Formula

9. Flux density  rate of flow of a property per unit area, which has the dimensions [quantity]/([time]·[area])  Rate of flow of electric current through per unit area of the cross-sectional area of the conductor  Tesla (symbol T) is SI derived unit for flux density  1 T = 1 N/Am T = tesla N = newton A = ampere

10. th umb th rust (force) f irst finger f ield Se c ond finger c urrent

11. Example

12. Ways to increase the force 1. Increase the current passing through the wire Increase p.d. of power source Use wire with less resistance ○ Thicker wires ○ Make from better conductors

13. Ways to increase the force 2. Use stronger magnets A.K.A magnets that have a greater magnetic field strength

14. Applications The Earth's magnetic field protects us from dangerous cosmic radiation from the Sun. Van Allen radiation belts around the Earth

15. References  http://www.google.com.sg/imghp?hl=en &tab=wi http://www.google.com.sg/imghp?hl=en &tab=wi  www.sparknotes.com www.sparknotes.com  spiff.rit.edu  www.physicsforums.com www.physicsforums.com  www.thefreedictionary.com www.thefreedictionary.com  en.wikipedia.org  farside.ph.utexas.edu