1. Lecture 23—Faraday’s Law Electromagnetic Induction AND Review of Right Hand Rules Monday, March 30

2. Electric Currents Also Create Magnetic Fields A long, straight wire A current loopA solenoid Slide 24-15

3. The Magnetic Field of a Straight Current-Carrying Wire Slide 24-16

4. Drawing Field Vectors and Field Lines of a Current-Carrying Wire Slide 24-21

5. The Magnetic Field of a Solenoid A short solenoidA long solenoid Slide 24-24

6. Example What is the direction and magnitude of the magnetic field at point P, at the center of the loop? Slide 24-30

7. The Force on a Charged Particle Moving in a Magnetic Field Slide 24-32

8. Magnetic Fields Exert Forces on Currents Magnitude of the force on a current segment of length L perpendicular to a magnetic field Slide 24-37

9. The Torque on a Dipole in a Magnetic Field Slide 24-43

10. Electromagnetic induction Lenz’s law Faraday’s law The nature of electromagnetic waves The spectrum of electromagnetic waves Electromagnetic Induction and Electromagnetic Waves Topics: Sample question: The ultraviolet view of the flowers on the right shows markings that cannot be seen in the visible region of the spectrum. Whose eyes are these markings intended for? Slide 25-1

11. Electromagnetic Induction Slide 25-8 Change magnetic field through coil, change the area of the coil, or change the angle coil makes with respect to the magnetic field.

12. Motional emf Slide 25-9

13. Magnetic Flux Slide 25-10

14. Lenz’s Law Slide 25-13 Lenz’s law There is an induced current in a closed, conducting loop if and only if the magnetic flux through the loop is changing. The direction of the induced current is such that the induced magnetic field opposes the change in the flux.

15. Homework due Wednesday Read: 23: 1-3 Faraday’s Law and electromagnetic induction Problems: 25: 1, 2, 4 38: torque on current loop 39: ditto WB 24: 23-30 forces on straight wires and torques on loops