Objecie F s w Tnsfome Moionl To be ble o fin nsfome. moionl nsfome n moionl. 331 1 331 Mwell s quion: ic Fiel D: Guss lw :KV : Guss lw H: Ampee s w Poin Fom Inegl Fom D D Q sufce loop H sufce H I enclose J enclose loop lecic i n mgneic fiels fil e no ele. l (is inepenenl. Then how oes n elecomgneic ( fiel eis? enclose F s peimen Hpohesis: If cuen coul inuce mgneic fiel (Ose s epeimen hen he mgneic fiel shoul be ble o inuce cuen. 3 ws h he mgneic fiel inuces cuen in coil. moing coil in h oes no chnges wih ime coil in he ime ing moing coil in ime ing 331 3 331 4
F sw Fom epeimen, cuen is inuce when o he posiion(e of he coil chnges wih ime. Quni ele o n e mgneic flu uen inuce b ing mgneic flu wih ime. Define h he cuen is inuce b elecic poenil iffeence clle elecomoie foce ( Ψ ol 331 5 Fs s s w( elecic poenil wihin he loop n is efine s follows. Ψ ol I is no necess h he close loop is he conucing loop. en s lw: The iecion of is in such iecion h euces he mgniue of he oiginl mgneic flu 331 6 lose oop in F s lw The following ssem is loce in he e whee he mgneic fiel oes no chnge wih ime. Does he lo eceies n cuen? luion: F sw Ψ Ψ ol ol wich is uning on n off he fequenc of 5H. o o chnges wih ime (Tnsfome nsfome onsie one insnce. Moing coil (Moionl moionl onsie one picul insnce. The mgneic flu insie he pink e is consn. No is inuce. Theefoe, hee is no cuen. AN 331 7 nsfome moionl 331 8
Poof: Tnsfome Ψ Ψ l ol Fom he efiniion ii of mgneic flu, No moemen, consn. 331 9 Poof: Moionl onsie consn so is inuce fom he chnge of coil s posiion (shpe. δ Ψol ( δ ( lim δ δ op boom sie lim lim δ δ δ δ δ sie lim δ δ sie ( 331 1 Moionl ( moionl Foce on he filmen cing inuce I in :, I F F I Foce esising he moemen. 331 11.1: Tnsfome I? Theoem: 1. F s lw:. Ohm s lw: V I 4 cm.cos5.75sin 4 1.cos314 T N5 uns, 1Ω nsfome moionl oluion: 1 Fin nsfome. nsfome 1loop 189.4sin 314 (1. 314 sin 314 331 1
.1: Tnsfome ( Fin fo 5 uns. nsfome 5 ( nsfome 1loop 3 No moion so moionl. Fin ol. 947 sin 314 nsfome moionl 947 sin 314 V 4 Fin cuen fom Ohm s lw. V 947sin 314 V I I 9.47sin314 A AN 1 5 Fin he iecion of he cuen. Posiie cuen is he iecion of he cuen hing he inuce in he sme iecion s. uen in iecion. AN 331 13 I.: uen n oss σ sin( T uen?, oss? Theoem: 1. F s lw: b nsfome moionl. Ohm s lw: V I 3. Powe: P VI [W] oluion: 1 Fin nsfome. nsfome No moion so moionl. Fin ol. nsfome moionl cos( ( ( π π cos( V 331 14.: uen n oss ( 3 Fin he iecion of he cuen. Negie cuen inices h he iecion is opposie. 4 Fin esisnce: uen in iecion. σ A π ( σ ( b 5 Fin cuen on ech hin esisnce: V π cos( σb cos( I π σ ( b 6 Inege fo he enie isc. σ b cos( I e A AN 4 331 15.: uen n oss (3 7 Fin powe loss in hin esisnce: σ b cos( P VI π cos( 8 Inege fo he enie isc: 4 πσb cos ( P 4 πσb 4 cos ( W AN 8 Quesion: Wh on we use P VI? 331 16
/s w.3: Moionl I? T l Theoem: 1. F s lw: nsfome moionl Ω Ohm s. lw: V I oluion: 1 oes no chnge wih ime nsfome. Fin onl moionl. moionl op ( sin cos cos boom cos 331 17 l.3: Moionl ( igh lef wcos Fin moionl (which is lso ol in his quesion. lef op wl cos wl cos V 3 Fin I b Ohm s lw. igh boom V wl cos V I I A AN 331 18.4: F s Disc Geneo I? /s /s T li oluion: Theoem: 1. F s lw: nsfome moionl. Ohm s lw: V I 1 oes no chnge wih ime nsfome. Fin onl moionl. moionl.4: F s Disc Geneo ( I Fin moionl (which is lso he ol in his quesion. moionl c lef 3 Fin I b Ohm s lw. op ( 1 igh V 1 V I I A AN boom 331 19 331
Noe: No-o n o Volge onsie he cse when he isc hs he esisnce. I? /s T oluion: The eluion fo is no ele o insie he isc so is he sme. onsie he equilen cicui. In he close loop,, V I No-lo olge: Open cicui ( V lo V o olge: V lo is less hn V becuse hee is he olge op in he isc 331 (geneo. 1 V A V V lo A w.5: Moionl A ighl woun ecngul coil hing N uns is oing in unifom mgneic fiel. Deemine he inuce in he coil. T N uns /s Theoem: 1. F s lw: nsfome moionl oluion: 1 ince oes no chnges wih ime. Fin onl moionl. moionl op ( sin cos cos boom cos 331 331.5: Moionl ( igh wcos lef w cos( 18 wcos Fin fo one loop. (ecll h nsfome so his is lso ol. 1loop /s T w N uns lef op igh boom w cos w cos wl cos AcosV 3 Fin fo N loop. loops ( N N 1loop N Acos V AN 3.5: Moionl (3 Meho : Using he oiginl fomul. Ψ Theoem: 1. F s lw: ol oluion: 1 Fin e of chnging flu in 1 loop Ψ 1loop ( ( ( cos sin Ae of ecngul coil A sin( A cos( ( ( 331 4
.5: Moionl (4 Fin chnging e of ol flu (N uns Ψ Ψ 1 N ol loop 3 Fin fom F s lw. Ψ ol ( N Acos N Acos V AN 4 Fin he iecion of he cuen b igh-hn ule: Posiie cuen is he iecion of he cuen hing he inuce in he sme iecion s. I AN.6: Moionl Tnsfome cos( T Theoem: 1. F s lw: nsfome moionl I?. Ohm s lw: V I oluion: 1 chnges wih ime. nsfome nsfome sin( ( sin( ( sin( ( 331 5 331 6.6: Moionl Tnsfome ( Thee is moion (fom he igh il. o fin moionl. cos( T moionl igh ih cos( ( cos( moionl cos( ( ( cos( 3 Fin ol nsfome moionl 4 Fin I b Ohm s lw. V V I I sin( cos( ( cos( sin( A AN 331 7 Diecion of he cuen is s shown b. AN.7: Moionl Tnsfome cos(cos(k T b (? oluion: Theoem: 1. F s lw: nsfome moionl 1 chnges wih ime. nsfome onsie when he lef sie of he loop is m. b sin( cos k ( nsfome sin( cos( k ( ( b sin( (sin( k( sin( k k 331 8
.7: Moionl Tnsfome ( Thee is moion in he loop. o fin moionl. moionl lef cos( cos( k ( cos( cos( k ( igh cos( cos( k( ( cos( cos( k( ( moionl b cos( cos( k b cos( cos( k( V o 3 Fin ol nsfome moionl b ( sin( i( k ( sin( i( k sin( i( k b cos( k cos( k( cos( ( Diecion of he cuen is s shown b. AN AN 331 9 Tnsfome : poin fom nsfome Fom oke s Theoem 331 3 Moionl : poin fom Moionl moionl Fom okes heoem ( Poin fom of moionl : ( 331 31 F s w: umm F s w: Inegl fom ( Poin fom ( onsie onl his p. 331 3