1 / 16

Announcements

Announcements. Homework for tomorrow… (Ch. 32, Probs. 16, 18, & 27) 32.4: a) –(3.2 x 10 -15 T) jhat b) 0 c) (1.0 x 10 -15 T) ihat 32.6: (2.8 x 10 -17 T) khat Office hours… MW 12:30-1:30 pm TR 9-10 am F 10-11 am Tutorial Learning Center (TLC) hours:

Download Presentation

Announcements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Announcements • Homework for tomorrow… (Ch. 32, Probs. 16, 18, & 27) 32.4: a) –(3.2 x 10-15 T) jhat b) 0 c) (1.0 x 10-15 T) ihat 32.6: (2.8 x 10-17 T) khat • Office hours… MW 12:30-1:30 pm TR 9-10 am F 10-11 am • Tutorial Learning Center (TLC) hours: M 8-1 pm, 3-6 pm, W 8-1 pm, 2-6 pm TR 8-6 pm, F 8-2 pm

  2. Chapter 32 The Magnetic Field (Magnetic Dipoles & The Magnetic Force on a Moving Charge)

  3. Review… The B-field of a current loop of radius R carrying a current I… The B-field of a coil of radius R with N turns carrying a current I…

  4. Electric dipole moment, revisited… • Electric dipole moment • E-field of a dipole on the dipoleaxis Notice: zis distance measured from the center of dipole. +q s -q

  5. 32.5: Magnetic Dipoles The B-field of a current loop… Notice: This field has rotational symmetry

  6. 32.5: Magnetic Dipoles The B-field of a magnetic dipole moment is…

  7. 32.5: Magnetic Dipoles The B-field of a magnetic dipole moment is… Notice: This result is valid on axis of dipole, when z >> R! where

  8. Comparing the Electric dipole moment to Magnetic dipole moment… The E-field of an electric dipole moment is… The B-field of a magnetic dipole moment is… +q s -q

  9. Quiz Question 1 What is the current direction in the loop? • Out at the top, in at the bottom. • In at the top, out at the bottom. • Either 1. or 2. would cause the current loop and the bar magnet to repel each other.

  10. 32.7: The Magnetic Force on a Moving Charge • After the discovery that electric current produces a magnetic field, Ampère set up two parallel wires that could carry large currents either in the same or opposite direction. • Ampère’s experiment showed that a magnetic field exerts a force on a current!

  11. 32.7: The Magnetic Force on a Moving Charge Ampere’s experiment implied that… a B-field exerts a force on a moving charge! Magnitude: Direction: given by RHR

  12. 32.7: The Magnetic Force on a Moving Charge Several important properties: • Only a moving charge experiences a magnetic force. • There is NO magnetic force on a charge moving parallel/antiparallel to a B-field. • When there is a force, the force is perpendicular to v & B • The force on a negative charge is in the direction opposite to • For a charge moving perpendicular to B, the magnitude of the magnetic force is

  13. Quiz Question 2 The direction of the magnetic force on the proton is • to the right. • to the left. • into the screen. • out of the screen. • The magnetic force is zero.

  14. Quiz Question 3 The direction of the magnetic force on the electron is • upward. • downward. • into the screen. • out of the screen. • The magnetic force is zero.

  15. i.e. 32.10: The magnetic force on an electron A long wire carries a 10 A current from left to right. An electron 1.0 cm above the wire is traveling to the right at a speed of 1.0 x 107 m/s. What are the magnitude and the direction of the magnetic force on the electron?

  16. Quiz Question 4 Which magnetic field causes the observed force?

More Related