Lect13 - ! " ! " # ! ! # 05 Force on a wire...

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Unformatted text preview: ! " ! " # ! ! # 05 Force on a wire carrying current I Cross sectional area A, Length L Number of charges/m3 = n Each charge moving at Vavg Force on each charge Total force on wire Feach Fwire q vavg B Nq vavg x B nAL qnAvavg N I N Feach Use Fwire B L 06 I Fwire IL B Current- carrying wire in uniform B field B I L Fwire IL B Out of page % F IL B A B C 08 $ % F IL B A B C 10 & % F IL B ( %+ , -+ . + / 12 ) " " * ' 1 A B C 2 13 3 # 4 0 1 y : x / 6 7 ! 3 8 6 " + * %+ -+ + 9+ 15 % % % / 6 8 8 8 3 8 5 1 y R F R F A B C D E 17 ; < " 9 < ! < " 9 =% " 19 B z 6 6 6 > B B y 6 z x x B y B 6 - 21 B I B / " 7 " " + z B B y 7 6 -+ x 22 1 Three different orientations of a magnetic dipole moment in a constant magnetic field are shown below. Which orientation results in the largest magnetic torque on the dipole? B - "" 24 6 B ? " ! " from 1 to ! ! B 1 Rotate 2 B 2 2 2 U 2 U1 1 B d 1 B sin d B cos 2 1 U 2 U1 B cos 2 B cos 1 2 B 1 B 27 $ U=0 Lowest U parallel to B 1.5 1 0.5 0 0 -0.5 -1 -1.5 30 60 90 120 150 Highest U antiparallel to B U 180 B 1 : Three different orientations of a magnetic dipole moment in a constant magnetic field are shown below. Which orientation has the most potential energy? ! 30 ' % Three different orientations of a magnetic dipole moment in a constant magnetic field are shown below. We want to rotate the dipole in the CCW direction. a a c B " ( *$( *$( *$( *$( 30 # $ & + + , , " $% " $% " $% " $% + , + , '( % ) % & '( $% + " " $% $% , # $( , ' 0 % Consider rotating the dipole to each of the three final orientations shown. a a c B % ) *. */ ( 30 & '( ( - " '" * ' ( ( # % " '" # 5 % 6 : ! % ! / 1 / 8 8 6 " 6 # 6 # 8)3 #% @3 8 # a z - z 30 . - y y A 6 ! ! " " ! B # ! / x % C C % ! 8 " 6 ! " = ( D F E=) " C C 32 % " " ! ; % 6 : ! % ! / 1 / 8 8 6 " 6 # 6 # 8)3 #% @3 8 # a z - z 30 . - y y / x ( * 7% + @8 z ! " 7-+ )8 z ! ! 7 +@ 79 + ) . x y IA 0 y 34 1 2 1 % 6 : ! % ! / 1 / 8 8 6 " 6 # 6 # 8)3 #% @3 8 # a z - z 30 . - y y / x ( * 7% + @8 7-+ )8 z 7 +@ - 79 + ) . y 0 36 % 6 : ! % ! / 1 / 8 8 6 " 6 # 6 # 8)3 #% @3 8 # a z - z 30 . - y y / x ( 7% + E G; z - " 7-+ E =; * 7 +E H; 900 y B 0 38 % 6 : ! % ! / 1 / 8 8 6 " 6 # 6 # 8)3 #% @3 8 # a z - z 30 . - y y / x ( 7% + E z - " G; z y " 7-+ E =; 7 +E &3 * H; ( % 4 ( 5 1200 B 0 y 40 ? % 6 : ! % ! / 1 / 8 8 6 " 6 # 6 # 8)3 #% @3 8 # a z - z 30 . - y U ( 7% + U z - B " 2 / x * Ia B 1 2 7-+ U 3 2 Ia B 2 7 + U 1 2 Ia B 2 B cos(120 ) o cos(120o ) U B 1 B 2 Ia 2 U 1 2 Ia B 2 $ y 44 ...
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This document was uploaded on 03/08/2012.

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