1 / 13

Lecture 21—Wednesday

Lecture 21—Wednesday. March 18 Magnetic Forces on Dipoles Magnetic Resonance Imaging. Quick Review of Monday. Force on a straight wire in a uniform B-field: Direction from right hand rule Force between two straight parallel conductors: Direction from right hand rule . Today.

dustin
Download Presentation

Lecture 21—Wednesday

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. Lecture 21—Wednesday March 18 Magnetic Forces on Dipoles Magnetic Resonance Imaging

  2. Quick Review of Monday • Force on a straight wire in a uniform B-field: • Direction from right hand rule • Force between two straight parallel conductors: • Direction from right hand rule

  3. Today • Force on a magnetic dipole in a magnetic field • Current loop is a magnetic dipole • Find torque on a planar current loop • Start with rectangular loop • Magnetic Resonance Imaging • Atoms are dipoles • But only two orientations wrt magnetic field, with or against. Difference in energy between the two orientations is in the radio frequency range for B≈1 T

  4. Bar magnet in uniform B-field • a • b • c • d c d

  5. Magnetic Fields Exert Torques on Current Loops Slide 24-42

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

  7. The Electric Motor Slide 24-46

  8. Magnetic Resonance Imaging Slide 24-44

  9. Magnetic Resonance Imaging Slide 24-45

  10. Quiz #8 • What magnetic field strength and direction will levitate the 2.0g wire? B-field in shaded region. 1.5A

  11. Homework due today • Homework due today • Problems: 24: 32, 34, 37 • 32: field strength and direction to levitate wire given mass and I • 34: F with wire not perpendicular to field • 37: force on current loop with radial field (loud speaker).

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

More Related