New Magnetic Field and Magnetic ForcesMagnetic 2012. 10. 18.¢  Magnetic Field and Magnetic ForcesMagnetic

  • View
    2

  • Download
    0

Embed Size (px)

Text of New Magnetic Field and Magnetic ForcesMagnetic 2012. 10. 18.¢  Magnetic Field and Magnetic...

  • Magnetic Field and Magnetic ForcesMagnetic Forces

    Chapter 27 October 18, 2012October 18, 2012

    October 18, 2012 Physics 208 1

  • Announcing New SI Peer Instructor for our class

    Jennifer King, jenn4k08_2012@neo.tamu.edu She will be hosting 3 SI sessions each week for the rest of the semestersemester.

    Sunday 5pm, Harrington 200 Monday 8pm, Harrington 203 T d 8 Bl k 105Tuesday 8pm, Blocker 105

    Tuesday- discuss topics covered that day in lecture Sunday- discuss topics covered in Thursday lecture Monday- review "tricky" concepts/address any lingering questions over previous week's material

    October 18, 2012 Physics 208 2

  • Exam 2 Results

    9

    10

    Exam 2 scores

    6

    7

    8

    n cy

    A – 90-100 B – 80-89 C – 70-79 D – 54-69

    3

    4

    5

    Fr eq

    u en

    Frequency

    D – 54-69 F – 0-53

    Exam Average

    0

    1

    2

    2 12 22 32 42 52 62 72 82 92 More

    72

    October 18, 2012 Physics 208 3

    Exam 2 score

  • Magnetic Force on a Moving Charge

    October 18, 2012 Physics 208 4

  • Flux of the Magnetic Field, ΦΒ

    Once again we introduce the idea of Flux. This time we calculate the flux of the magnetic field through a surfacesurface……….

    October 18, 2012 Physics 208 5

  • Calculating flux…….

    October 18, 2012 Physics 208 6

  • October 18, 2012 Physics 208 7

  • Velocity Selector

    rrrrr

    BvqEq

    BvqEqFFF electricmagnetictotal rvr

    rvrrrr

    ×=

    ×+−=+==

    or

    0

    October 18, 2012 Physics 208 8

    BvqEq ×=or

  • The Mass Spectrometer

    October 18, 2012 Physics 208 9

  • Mass Spec (cont.)

    EvBvqEq so× rvr

    qBRmv B

    vBvqEq

    thenand

    so =×=

    RqB qBRmv

    2

    then and =

    E qm =

    October 18, 2012 Physics 208 10

  • The Cyclotron

    October 18, 2012 Physics 208 11

  • Cyclotron Frequency

    revolutionahalf onefor Time

    )/(

    velocity distance

    2 1 BRmq

    R v RT ππ ===

    radius theoft independen is this:Note so

    )/(velocity

    2 1 qB

    mT

    BRmqv π

    = 2 qB

    October 18, 2012 Physics 208 12

  • October 18, 2012 Physics 208 13

  • Force on a current carrying wire in a magnetic field…..

    Remember that a wire is carrying moving charges with a velocity of vdrift

    October 18, 2012 Physics 208 14

  • October 18, 2012 Physics 208 15

  • Example..

    October 168 2012 Physics 208 16

  • October 168 2012 Physics 208 17

  • A more complicated loop to consider….

    October 18, 2012 Physics 208 18

  • October 18, 2012 Physics 208 19

  • Force on a current loop in a uniform field.

    October 18, 2012 Physics 208 20

  • Torque on a current carrying loop

    getweloopfor thesoFr rrr

    ×=τ

    get weloopfor theso

    B

    Fr rrr

    ×=

    ×=

    μτ

    τ

    looptheofplanethetonormal vector a is where ANI rr

    =μ oopt eop a et etoo avectoas

    October 18, 2012 Physics 208 21

  • Potential Energy of a dipole in a magnetic field

    dipolemagneticthisofenergypotentialThe thenis field B uniform ain

    dipolemagnetic thisofenergy potential The

    BU rr

    ⋅−= μ

    October 86, 2012 Physics 208 22

Related documents