Uyini umsinga kagesi? Okokuqala khumbula, iyiphi incazelo yamanje esiyifundile?

Kalula nje, ukunyakaza okuqondisayo kwezinhlayiya ezikhokhisiwe ku-conductor kungumbane kagesi.

Kuphela uma into ishaje izinhlayiya ezikwazi ukuhamba ngokukhululeka, ingadlulisela amandla kagesi—okungukuthi, ukuhambisa ugesi. Lezi zinhlayiya ezikhokhisiwe ezibamba iqhaza ekuqhubeni zibizwa ngokuthi abathwali. Ezinsimbi, isibonelo, ama-electron angaphandle ama-athomu kuphela angasebenza njengabathwali.

“Ukunyakaza kokuqondisa” ekuchazeni kwamandla kagesi kuvame ukuqondwa kabi. Abantu abaningi bacabanga ukuthi libhekisela ekuhambeni ngendlela ethile, akunjalo! Ingabe isiqondiso sokunyakaza kwama-electron kusekethe ye-AC ayishintshi?

Eqinisweni, i-orienteering ihlobene “nokunyakaza okungahleliwe”!

Njengoba ama-electron eyizinhlayiya ezincane kakhulu, kufanele ahlale enyakaza okushisayo ngaso sonke isikhathi. Ukunyakaza okushisayo kuwukunyakaza okungahleliwe, njengoba kukhonjisiwe emfanekisweni ongezansi.

Lokhu kunyakaza empeleni kuyashesha kakhulu. Ngokwesibonelo, ezinsimbi ezisezingeni lokushisa elilingana negumbi, isivinini sokunyakaza kwe-electronic thermal silingana namakhulu amakhilomitha ngomzuzwana!

Uma ubhekisisa lokhu kunyakaza okungahleliwe, uzothola ukuthi isiqondiso sokunyakaza kwezinhlayiyana ngayinye ahleliwe nganoma yisiphi isikhathi. Uma uhlanganisa amavekhtha esivinini alezi zinhlayiya, umphumela ucishe ube uziro.

Manje engeza insimu kagesi kumqhubi, futhi i-electron iphakamisa ukunyakaza okuqondisayo ngesisekelo sokunyakaza okungahleliwe. Uma sicabanga ukuthi insimu kagesi ingakwesobunxele isikhathi esithile, ukunyakaza kwama-electron kubukeka kanjena. Amabhola abomvu amelela ama-athomu ensimbi ku-crystal lattice, futhi amachashazi ahamba ngokushesha amele ama-electron amahhala.

Ingabe ibukeka ishesha? Lokho kungenxa yokuthi ukunyakaza kwe-elekthronikhi kuyashesha ngempela! Kodwa empeleni, ukunyakaza okungahleliwe, okufaka ingxenye enkulu yakho, akufaki isandla kumanje. Lapho ukunyakaza okungahleliwe kususwa, okunye kufana nokubukeka okunensayo okungezansi.

Ngempela, ukunyakaza okuqondile kwama-electron kuhamba kancane kunejubane lokunyakaza okushisayo. Lokhu “kugaya” ukunyakaza kwama-electron kubizwa ngokuthi i-drift, noma “drift”. Ngezinye izikhathi, ama-electron azogijima aye kolunye uhlangothi ngenxa yokushayisana nama-athomu. Kodwa ngokuvamile, ama-electron ahamba ohlangothini olulodwa.

Uma inkambu kagesi ishintsha isiqondiso, isiqondiso se-electron drift nayo izoshintsha.

Ngakho-ke, lolu hlobo lokunyakaza okuqondisayo lusho ukuthi isamba sesivinini sawo wonke ama-electron abamba iqhaza ekuqhubeni ngesikhathi esithile akuyona i-zero, kodwa ngokuvamile isendleleni ethile. Lesi siqondiso singashintshwa noma kunini, futhi lokho kuyindaba yokushintshana kwamandla.

Therefore, current is not so much the “directional movement” of electric charge as it is the “collective movement” of electric charge.

Ubukhulu bamanje ku-conductor buboniswa ngamandla amanje. Ukuqina kwamanje kuchazwa njengenani likagesi elidlula esigabeni esiphambanayo sekhondatha ngesikhathi seyunithi, okungukuthi

Sifunde amanani athile aphathekayo aqukethe igama elithi “intensity”, njengamandla enkundla kagesi kanye namandla kazibuthe. Ngokuvamile zimelela ukwabiwa kwesikhathi seyunithi, indawo yeyunithi (noma iyunithi yevolumu, iyunithi ye-engeli eqinile). Nokho, igama elithi “ukuqina” ekushubeni kwamanje alibonisi ukwabiwa kwendawo kwamanje.

Eqinisweni, elinye inani elibonakalayo linesibopho sokusatshalaliswa kwamanje endaweni, okuwukuminyana kwamanje.

Njengoba ingqikithi yamanje kagesi iwukuhamba kokuqondisa kweshaja kagesi, kufanele kube nobudlelwano obuthile phakathi kokuqina kwamanje kanye nesivinini sokukhukhuleka!

In order to obtain this relationship, we must first clarify a concept-carrier concentration, that is, the number of carriers in a unit volume, which is expressed by .

Kucatshangwa ukuthi isigaba esiphambanayo sikakhondatha siwukuthi, ukugxiliswa kwenkampani yenethiwekhi kungukuthi, isivinini sokukhukhuleka sinjalo, kanye neshaji elishajiwe.

Then the charge in the conductor on the left side of the surface is, and these charges will pass through the surface within a certain period of time, so

Lokhu ukubonakaliswa okuncane kakhulu kokuqina kwamanje.

Ukuminyana kwamanje ukwahlukaniswa kwamandla wamanje nendawo, ngakho-ke ubukhulu bokuminyana bamanje bunjalo, kodwa buchazwa njengevekhtha, futhi isiqondiso isiqondiso se-drift velocity vector yezinkampani zenethiwekhi ezishajwe kahle, ngakho-ke ukukhukhuleka kwama-electron insimbi ingatholakala kule Speed, njengesibonelo esingezansi.

Cabanga ngocingo lwethusi, ucabanga ukuthi i-athomu yethusi ngayinye inikela nge-electron njengesithwali. Kukhona i-mol engu-1 yethusi, umthamo wayo uwukuthi, isisindo se-molar siwukuthi, ukuminyana yikho, khona-ke ukuhlushwa komthwali wocingo lwethusi

Iphi i-Avogadro njalo. Ukuminyana kwethusi kuyatholakala, futhi inani elitholwe ngokufaka esikhundleni limayelana neyunithi/cubic meter.

Uma sicabanga ukuthi irediyasi yocingo lwethusi ingu-0.8mm, ukugeleza kwamanje kungu-15A, =1.6 C, futhi isivinini sokukhukhuleka sama-electron sibalwa njenge

Kuyabonakala ukuthi ijubane lokukhukhuleka lama-electron lincane kakhulu.

Kulabo abafunda amasekethe, okungenhla incazelo ephelele yamanje.

Kodwa ku-physics, incazelo engenhla yamanje empeleni iyincazelo encane kuphela. Imisinga evamile ayikhawulelwe kumakhondakta, inqobo nje uma ukunyakaza kwamashaji kagesi kusasebenza. Ngokwesibonelo, lapho ama-electron e-athomu ye-hydrogen ezungeza i-nucleus, kwakheka amandla kagesi emzileni wawo.

Ake sithi inani lenkokhelo ye-elekthronikhi liyisikhathi sokunyakaza. Bese kuthi ngaso sonke isikhathi lapho kudlula, kuba nenani elikhulu kangaka lenkokhelo elidlula kunoma iyiphi ingxenye ephambanayo yeluphu, ngakho-ke ukuqina kwamanje kusekelwe ebudlelwaneni phakathi kwesikhathi, imvamisa kanye nesivinini se-angular, futhi yamanje nayo ingavezwa njenge

For another example, a charged metal disk, rotating around its axis, also forms loop currents with different radii.

Lolu hlobo lwamanje aluyona i-conduction yamanje evamile futhi alukwazi ukukhiqiza ukushisa kwe-Joule! Ayikwazi ukwenza umjikelezo wangempela.

Uma kungenjalo, unganginika isibalo sokuthi kungakanani ukushisa kwejoule okukhiqizwa ngomzuzwana ngama-electron e-athomu ye-hydrogen?

In fact, the current in vacuum does not satisfy Ohm’s law. Because, for the electric current formed by the movement of charged particles in the vacuum, the carriers are not collided similar to the lattice in the metal, so the vacuum has no resistance and no conductance.

Ukunyakaza kwamashaji kagesi kukhiqiza amandla kagesi, futhi ishaja kagesi ngokwayo ijabulisa insimu kagesi. Lokhu kulula ukudala ukungezwani. Ngakho-ke abantu abaningi bacabanga ukuthi inkambu kagesi yezinhlayiya ezishajwayo ezakha amandla kagesi kumele zivezwe. Kodwa empeleni, ngenxa yamanje conduction ku-conductor jikelele, abathwali bageleza kungemuva esakhiwe inombolo enkulu ion zensimbi positively charged, futhi umqhubi ngokwawo angathathi hlangothi!

Sivame ukubiza lolu hlobo lwamanje olukhethekile ngokuthi “i-equivalent current”. Okulinganayo lapha kusho ukuthi ikhiqiza insimu kazibuthe ngesisekelo esifanayo nesokuqhutshwa komshini ojwayelekile!

Isikhumbuzi: Ungaphambanisi “i-equivalent current” lapha “nesekhethi elinganayo” ekuhlaziyeni isifunda.

In fact, when we first studied the magnetic field, the electric current in Biot-Saffar’s law was the generalized electric current that contained this equivalent current. Of course, the conduction current in Maxwell’s equations also refers to the generalized current.

Labo abaye bafunda umphumela we-photoelectric bayazi ukuthi lapho i-photoelectron idonsa isuka ku-cathode iye ku-anode, uma ithonya lomoya linganakwa, lokhu okwamanje kubangelwa ukunyakaza kwamashaji kagesi ku-vacuum, futhi akukho ukumelana, ngakho-ke. ayinqunyelwe umthetho ka-Ohm.

Ngakho-ke, ingabe lokhu ukuphela kwento mayelana namandla kagesi ku-physics?

Cha! Kukhona futhi izinhlobo ezimbili, okuyi-magnetizing current kanye ne-displacement current.

Futhi zingama-currents amabili alinganayo, okuthi, njengoba negama libonisa, aphinde ethulwe ukuchaza i-magnetism. Ngamanye amazwi, baye bahlukana nesici esiyisisekelo “sokunyakaza kokukhokhiswa” kwamanje!

Kuyamangaza lokho! Akukho ukunyakaza kokushaja kagesi, kungani-ke kungabizwa ngokuthi i-electric current?

Ungakhathazeki, futhi ungilalele kancane.

Ake sibheke amandla kazibuthe kuqala.

Kwatholakala ukuthi uzibuthe ubangelwa ukuhamba kukagesi (ungabheki incazelo kazibuthe ngezakhiwo zangaphakathi ze-spin okwamanje). Ukuze sichaze i-magnetism yemvelo, isazi sefiziksi saseFrance u-Ampere sabeka phambili umbono “wokujikeleza kwamangqamuzana”.

Njengoba kuboniswe emfanekisweni ongezansi, noma iyiphi i-athomu noma i-molecule ingabhekwa njengeshaja kagesi ezungeza phakathi nendawo, yakhe i-loop current encane, okungukuthi, “ukujikeleza kwamangqamuzana”.

Ngokomthetho wokuthi amandla kagesi avusa amandla kazibuthe, lokhu kujikeleza kwamangqamuzana kuzokhiqiza inani elibonakalayo elibizwa ngokuthi umzuzu kazibuthe. Ubukhulu bayo buyindawo evalwe ukuzungeza kwamangqamuzana okuphindaphindwa amandla alinganayo okujikeleza kwamangqamuzana, futhi isiqondiso sawo sisebuhlotsheni obuzungezayo obusesandleni sokudla nesiqondiso sokujikeleza, okungukuthi.

Ngokusobala, isiqondiso somzuzu kazibuthe sihambisana ncamashí nendawo yamagnetic eyakhiwe amandla ajikelezayo

.

Ngaphansi kwezimo ezijwayelekile, ukuhlelwa kokujikeleza kwamangqamuzana ento kunesiphithiphithi, ngakho-ke into ayiyona kazibuthe, njengoba kuboniswe ngakwesokunxele somfanekiso ongezansi. Uma ingaphansi kwamandla kazibuthe angaphandle, lokhu kujikeleza kwamangqamuzana kuzocishe kuhlelwe kahle. Njengoba kuboniswe ngakwesokudla somfanekiso ongezansi, izikhathi zawo uzibuthe zihlelwa ohlangothini olulodwa ngangokunokwenzeka, njengezinaliti ezincane ezingenakubalwa eziqoqwe ndawonye ukuze zakhe insimu ephelele kazibuthe, futhi yonke into eyakhiwe ngazo iba kazibuthe.

Ake sithi kukhona uzibuthe oyi-cylindrical, ukujikeleza kwamangqamuzana kwangaphakathi kuhlelwe kahle, futhi izingxenye zokujikeleza kwamangqamuzana emaphethelweni esigaba sikazibuthe zixhunywe ndawonye ukuze zenze ukujikeleza okukhulu, njengoba kuboniswe esithombeni esingezansi.

Ngokusekelwe kulokhu, singacabanga ukuthi uzibuthe webha ufana ne-solenoid enamandla. Ngamanye amazwi, kukhona umsinga ongabonakali obanjwe phezu kukazibuthe! Lolu hlobo lwamanje alukwazi ukuxhunywa futhi lusetshenziswe. Ivalelekile ebusweni bukazibuthe. Siyibiza ngokuthi “i-binding current” noma “magnetizing current”.

Ngakho-ke, i-magnetizing current iyinhlangano yamanje, ngoba ifana neyamanje eyenziwe ngokuhamba kwamashaji kagesi wangempela, angakwazi ukukhiqiza ngokulinganayo insimu yamagnetic!

Ake sibheke umsinga wokugudluza futhi.

Ngokuvumelana ne-loop theorem ye-Ampere, okubalulekile kwamandla kazibuthe endleleni evaliwe ilingana nokugeleza kokuminyana kwamanje kunoma iyiphi indawo egobile eboshwe yile ndlela, okungukuthi, le theory ibizwa ngokuthi i-Stokes’ theorem kwizibalo. Lisitshela ukuthi ingxenye ehlangene yevekhtha ngakunoma iyiphi indlela evaliwe kufanele ilingane nokugeleza kokugoqa kwayo (lapha) kunoma iyiphi indawo eboshwe umzila ovaliwe.

Njengoba kuyitiyori yezibalo, kufanele ihlale ilungile, ngoba izibalo ziwuhlelo olunengqondo olusekelwe kuma-axiom.

Therefore, the Ampere Loop Theorem must always hold!

Nokho, isazi sefiziksi saseScotland esinekhono uMaxwell sathola ukuthi lapho sibhekene nesifunda esingazinzile, i-Ampere loop theorem yayiphikisana.

Umsinga ongazinzile ojwayelekile uyenzeka ngesikhathi sokushaja nokukhipha i-capacitor. Njengoba kuboniswe esithombeni esingezansi, kukhona i-current engazinzile ngesikhathi esifushane sokushaja kwe-capacitor.

Kodwa isifunda sinqanyuliwe phakathi kwamapuleti e-capacitor, okuzodala inkinga enkulu.

Ake sithi sicabangela indlela evaliwe edlula ucingo, njengoba kukhonjisiwe emfanekisweni ongezansi, umbuthano ophawulwe ngu-C, kanye nendawo egobile nawo njengomngcele ungakhethwa ngokungafanele. Emfanekisweni, indiza eyisiyingi ehlanganiswe ngu-C ngokwayo futhi ngaphesheya kwe-capacitor ikhethiwe. Indawo egobile yepuleti elingakwesokunxele.

Ngokusho kwendawo eyindilinga, kungabonakala ukuthi ngokusho kwendawo egobile, kodwa njenge-loop ebalulekile yamandla kazibuthe, inani layo kufanele linqunywe!

Ungayenza kanjani?

UMaxwell ukholelwa ukuthi i-loop theorem ye-Ampere kufanele isungulwe. Manje njengoba sekunenkinga, kufanele kube yingoba ingxenye yamandla kagesi ayizange itholwe yithi ngaphambili, kodwa ikhona!

Ngakho-ke, ungathola kanjani le ngxenye yamanje?

Njengoba inkinga iphakathi kwamapuleti, qala phakathi kwamapuleti.

Ngokuhlaziya, uMaxwell wathola ukuthi kungakhathaliseki ukuthi uyashajwa noma uyakhishwa, kunenani elibonakalayo phakathi kwamapuleti e-capacitor ngaso sonke isikhathi elivunyelaniswa nobukhulu nokuqondiswa kwamandla amanje. Isikhathi sokuphuma kokugeleza kwe-vector kagesi yokugudluzwa, okungukuthi, ichazwa ngokuthi i-displacement current.

Uma kubhekwa ukuthi le ngxenye iyingxenye yamanje engakaze itholwe ngaphambili, khona-ke i-current ephelele manje. Okusho ukuthi, nakuba isifunda phakathi kwamapuleti sinqanyuliwe, i-derivative of the electric displacement flux kanye nesamba samanje ndawonye, ​​​​sewonke , Qinisekisa ukuqhubeka kwamanje ngaso sonke isikhathi.

Ukubuyela emuva ekuphikisaneni kwangaphambilini, manje sesiyazi ukuthi, ngokwezidingo ze-theorem ye-Stokes, lapho kubalwa ukugeleza komthamo wamanje wendawo evaliwe, ukuminyana kokufuduka kwamanje kufanele kucatshangelwe, okungukuthi, i-ampere loop ephelele. Ngakho-ke i-theorem ithi, “Ngokuthola” le ngxenye entsha yamanje, inkinga ye-Ampere Loop Theorem iyaxazululwa!

Isizathu sokuthi kungani “isingeniso” singasetshenziswa lapha, kodwa elithi “discovery” lisetshenziswa lapha. Engifuna ukukugcizelela ukuthi lolu hlobo lwamanje alusona isinxephezelo sezibalo, kodwa luyinto yangempela, kodwa alukaze lutholakale ngaphambili.

Kungani ikhona kwasekuqaleni? Ngenxa yokuthi isebenza njengombane kagesi, njenge-conduction current, ijabulisa insimu yamagnetic ngokulinganayo, ngaphandle kokuthi akukho ukunyakaza kwamashaji kagesi, akukho cingo oludingekayo, futhi akukho ukushisa kwe-Joule okungakhiqizwa, ngakho-ke kuye kwanganakwa!

Kodwa empeleni ikhona ngokwayo, gcina iphrofayili ephansi, ibilokhu ijabulisa buthule insimu kazibuthe lapho ngaso sonke isikhathi!

Ngamanye amazwi, uma sibhekene nenkundla kazibuthe, incazelo yoqobo yamanje yincane kakhulu. Ingqikithi yamanje kagesi ayikona ukunyakaza kokushaja kagesi, kufanele kube yinto engajabulisa insimu kazibuthe.

Kuze kube manje, izinhlobo eziningana zamanje sezethuliwe. Zonke zikhona ngendlela eqondile, futhi ezifana ngazo ukuthi yonke imisinga ingavusa ngokulinganayo insimu kazibuthe.