1. TOC 1 Physics 212 and 222 Magnetic Forces Magnetic Force on a Moving Charge Magnetic Force on a Current Carrying Wire

2. TOC 2 Physics 212 and 222 Magnetic Forces 1.Point the fingers of your right hand in the direction of the vector A. 2.Curl your fingers toward the direction of the vector B. 3.The cross-product vector C is given by the direction of your thumb.

3. TOC 3 Physics 212 and 222 Magnetic Forces A vector A points to your right. Vector B points up. What is the direction of the cross product of A and B? A.To the right B.Up C.Toward you D.Away from you

4. TOC 4 Physics 212 and 222 Magnetic Forces A vector A points to north. Vector B points west. What is the direction of the cross product of A and B? A.To the right B.Up C.Toward you D.South

5. TOC 5 Physics 212 and 222 Magnetic Forces A vector A points toward you. Vector B points up. What is the direction of the cross product of A and B? A.To the right B.Up C.To the left D.West

6. TOC 6 Physics 212 and 222 Magnetic Forces Magnetic Force on Charge Particles the charge must be moving relative to the magnet creating the magnetic field. the velocity of the charge must not be parallel to the direction of the magnetic field. The force due to the magnetic field on a moving charge is The force on a positive charge has a direction given by the right-hand rule and has the magnitude qvB. For a negative charge the direction reverses. The SI units of magnetic field are Tesla (T) or Gauss. (1 Gauss = 10 -4 T)

7. TOC 7 Physics 212 and 222 Magnetic Forces An electron is moving with a speed of 3x10 6 m/s is inside a magnetic field of 20 T. The electron is moving to the right. The magnetic field is up. What is the magnitude of the force on the electron in pN? 9.61 0.01

8. TOC 8 Physics 212 and 222 Magnetic Forces An electron is moving with a speed of 3x10 6 m/s is inside a magnetic field of 20 T. The electron is moving to the right. The magnetic field is up. What is the direction of the force on the electron? A.Toward you B.Away from you C.North D.South

9. TOC 9 Physics 212 and 222 Magnetic Forces An proton beam (with 6.02x10 23 protons) has a speed of 3x10 6 m/s inside a magnetic field of 20 T. The beam is moving to the right. The magnetic field is up. What is the magnitude of the force on the beam in TN? 5.79 0.01

10. TOC 10 Physics 212 and 222 Magnetic Forces An proton beam (with 6.02x10 23 protons) has a speed of 3x10 6 m/s inside a magnetic field of 20 T. The beam is moving to the right. The magnetic field is up. What is the direction of the force on the beam? A.Toward you B.Away from you C.North D.South

11. TOC 11 Physics 212 and 222 Magnetic Forces Begin with the force on each element of charge The total charge (remember that they are electrons) passing through the wire in a given time dt is given by I The speed of the electrons as they move through the wire is So that

12. TOC 12 Physics 212 and 222 Magnetic Forces An wire segment with a current of 20 A and a length of 2 cm is placed inside a magnetic field of 15 T. The current is moving to the right. The magnetic field is up. What is the magnitude of the force on the wire in N? 6060

13. TOC 13 Physics 212 and 222 Magnetic Forces An wire segment with a current of 20 A and a length of 2 cm is placed inside a magnetic field of 15 T. The current is moving to the right. The magnetic field is up. What is the direction of the force on the wire? A.Toward you B.Away from you C.North D.South

14. TOC 14 Physics 212 and 222 Magnetic Forces Magnetic Force on a Moving Charge Magnetic Force on a Current Carrying Wire