Tanthauzo la Mphamvu yamagetsi
Mu conductor monga mkuwa, pali ma elekitironi omwe amayenda mwachisawawa pa liwiro lalikulu koma satuluka mu chitsulocho. Ma elekitironi omwe amatha kuyenda momasuka amatchedwa ma elekitironi aulere. Ngakhale ma elekitironi amayenda momasuka mbali zonse, palibe kuyenda konse kwa ma elekitironi mbali ina. Izi zimachitika pamene palibe kusiyana komwe kungachitike pakati pa malekezero awiri a waya wamkuwa.
Pamene waya walumikizidwa ku gwero lamagetsi, kusiyana komwe kungachitike kumachitika pakati pa malekezero awiri a waya wamkuwa, kotero kuti gawo lamagetsi limawonekera mkati mwa waya wamkuwa. Kukhalapo kwa gawo lamagetsi kumapangitsa ma elekitironi aulere kuti amve mphamvu yamagetsi F = q E = e E, komwe F = mphamvu yamagetsi , e = mphamvu yamagetsi, E = gawo lamagetsi . Mphamvu yamagetsi iyi imapangitsa ma elekitironi onse omwe akuyenda momasuka kuti ayende limodzi, komwe kuli mbali yomweyo ndi mphamvu yamagetsi.
Ma electron aulere omwe amasuntha pamodzi ali pakati pa ma atomu omwe amakhalabe mu waya wamkuwa kotero kuti ma electron onse amagundana ndi ma atomu. Kugundana kumeneku kumapangitsa kuti ma electron aulere asinthe. Ma electron onsewa nthawi zonse amakumana ndi mphamvu yamagetsi kotero kuti ma electron onse amafulumizitsidwa mbali imodzi ndi njira ya mphamvu yamagetsi. Pambuyo poyenda kwakanthawi, ma electron aulere amagundana ndi ma atomu mu waya wamkuwa. Koma ma electron aulere nthawi zonse amakumana ndi mphamvu yamagetsi kotero kuti ma electron onse amafulumizitsidwanso. Chifukwa chake kupatula kusuntha mwachisawawa mbali zosiyanasiyana, ma electron onse aulere amasunthanso pang'onopang'ono pamodzi mbali ya mphamvu yamagetsi komanso mbali ina ya mphamvu yamagetsi. Njira ya mphamvu yamagetsi imachokera ku mphamvu yamagetsi yayikulu kupita ku mphamvu yamagetsi yochepa, pomwe ma electron amasuntha kuchoka ku mphamvu yotsika kupita ku mphamvu yayikulu. Kusuntha mwachisawawa kwa electron iliyonse yaulere kumakhala ndi liwiro lachangu kwambiri, pomwe kuyenda ndi ma electron aulere mbali ya mphamvu yamagetsi kumakhala ndi liwiro lochepa kwambiri. Kusuntha kumeneku ndi ma electron aulere mbali ya mphamvu yamagetsi kumatchedwanso liwiro la drift.
Mphamvu yamagetsi imatanthauzidwa ngati kuyenda kwa mphamvu yamagetsi kudzera mu gawo lodutsa la kondakitala panthawi inayake. Mogwirizana ndi mgwirizano, njira ya mphamvu yamagetsi ndi yofanana ndi njira ya mphamvu yamagetsi yabwino. Mgwirizanowu unapangidwa asanadziwike kuti chomwe chimayenda mu kondakitala ndi ma electron opanda mphamvu omwe ali ndi mphamvu yoipa. Njira ya kayendedwe ka ma electron mu kondakitala ndi yosiyana ndi njira ya mphamvu yamagetsi. Chifukwa chake ngati tikambirana za mphamvu yamagetsi yomwe ikuyenda mu kondakitala, tanthauzo lake ndi kuyenda kwa mphamvu yamagetsi yabwino, komwe kumatchedwanso mphamvu yamagetsi yachikhalidwe chifukwa ndi zotsatira za mgwirizano.
Kuyerekeza kwa magetsi amagetsi
Mwa masamu, mphamvu yamagetsi imafotokozedwa ndi equation:
I = Δ Q / Δt
I = magetsi, ΔQ = kuchuluka kwa mphamvu yamagetsi, Δt = nthawi yopuma.
Gawo la magetsi amagetsi
Gawo la mphamvu yamagetsi ndi Coulomb, gawo la nthawi ndi lachiwiri, kotero gawo la mphamvu yamagetsi ndi Coulomb/sekondi. Coulomb/sekondi amatchedwanso Ampere, dzina la katswiri wa sayansi ya zaku France Andre Marie Ampere (1775-1836). 1 Ampere = 1 Coulomb/sekondi (1 A = 1 C/s). Mwanjira ina, mphamvu yamagetsi ya Ampere imodzi ndi yofanana ndi mphamvu yamagetsi ya Coulomb imodzi yomwe imadutsa m'dera la waya kwa sekondi imodzi. Kupatula kufotokozedwa mu Amperes, mphamvu yamagetsi imafotokozedwanso mu milliamperes (1 mA = 10 -3 A), microamperes (1 μA = 10 -6 A), nano amperes (1 nA = 10-9 A) kapena picoamperes (1 pA = 10 -12 A).
Chitsanzo cha vuto 1:
Mphamvu ya ma Ampere awiri imadutsa mu waya kwa masekondi 8. Dziwani kuchuluka kwa mphamvu yomwe imadutsa mu mfundo ndi kuchuluka kwa ma elekitironi omwe ali mu mphamvuyo!
Zodziwika:
Mphamvu yamagetsi (I) = 1 Ampere
Nthawi yopuma (t) = masekondi 2
Kufunidwa: mphamvu (Q) ndi chiwerengero cha ma elekitironi (e)
yankho;
Equation ya magetsi:
Ine = Q/t
I = magetsi amphamvu, Q = mphamvu yamagetsi, t = nthawi yopuma
Chaji yamagetsi:
Q = It = (2 Ampere)(masekondi 8) = 16 C.
Mphamvu ya elekitironi imodzi ndi 1.6 x 10 -19 Coulomb, kotero mphamvu ya Coulombs 16 ili ndi ma elekitironi ambiri monga 16 C / 1.6 x 10 -19 Coulomb = 10 x 10 19 ma elekitironi.
Mphamvu yamagetsi, liwiro la kusuntha, ndi kuchuluka kwa mphamvu yamagetsi
Unikani mphamvu yabwino yomwe ikuyenda bwino ndi liwiro, ikusuntha v kupita ku gawo lamagetsi E
pa kondakitala yomwe ili ndi malo opingasa A. Mphamvu yabwino imasuntha mpaka s = vt panthawi ya t.
Ngati chiwerengero cha tinthu tomwe timapatsidwa mphamvu pa voliyumu iliyonse (kuchuluka kwa tinthu tomwe timapatsidwa mphamvu) ndi n ndipo voliyumu ya kondakitala ndi A s = A vt,
ndiye kuti chiwerengero cha tinthu tating'onoting'ono tomwe timayatsidwa mu voliyumu ya kondakitala ndi n A v t. Ngati tinthu tating'onoting'ono tomwe timayatsidwa tili ndi mphamvu ya q ndiye kuti kuchuluka kwa mphamvu yomwe imadutsa kumapeto kwa kondakitala panthawi ya t ndi Q = nq A v t. Chifukwa chake, mphamvu yamagetsi yomwe ikuyenda kudzera mu nsonga ya kondakitala ndi I = Q / t = nq A v. Pomwe kuchuluka kwa mphamvu yamagetsi kapena mphamvu yamagetsi pa dera lililonse A ndi J = I / A = nq v.
Tinganene kuti mphamvu yamagetsi yomwe ikuyenda mu kondakitala ndi zotsatira za kuchulukitsa kwa kuchuluka kwa tinthu tomwe timayatsidwa (n),
kuchuluka kwa mphamvu ya tinthu tating'onoting'ono (q), dera la kondakitala (A) ndi liwiro la tinthu tating'onoting'ono tomwe timayendetsedwa (v).
Phunzirani zitsanzo zotsatirazi za mafunso.
Chitsanzo cha vuto 2:
Mphamvu yokhazikika ya ma amperes 10 imayenderera mu waya wamkuwa wokhala ndi gawo lopingasa la 3 x 10 -6 m2 . Kuchuluka kwa ma elekitironi aulere ndi ma elekitironi 8.4 x 10 28 /m3 . Dziwani liwiro la kusuntha kwa ma elekitironi aulere!
Zodziwika:
Mphamvu yamagetsi (I) = 10 Ampere
Malo olumikizirana ndi waya (A) = 3 x 10 -6 m2
Kuchuluka kwa ma elekitironi kwaulere (n) = 8.4 x 10 28 m -3
Mphamvu ya ma elekitironi (q) = 1.6 x 10 -19 C
Kufunidwa: Liwiro la kusuntha kwa ma elekitironi kwaulere (v)
yankho;
Liwiro la ma elekitironi limawerengedwa pogwiritsa ntchito njira yomwe idapezeka kale:
I = magetsi, n = kuchuluka kwa tinthu tomwe timayendetsedwa = kuchuluka kwa ma elekitironi, q = mphamvu imodzi ya elekitironi, A = dera lozungulira la woyendetsa, v = liwiro la kusuntha kwa elekitironi
Liwiro la kusuntha kwa ma elekitironi ndi 0.248 x 10 -3 mamita/sekondi = 0.248 mamilimita/sekondi.
Ma electron aulere amayenda pamodzi mu waya pa liwiro la mamilimita 0.248 pa sekondi. Mwanjira ina, sekondi iliyonse, ma electron onse aulere amayenda mpaka mamilimita 0.248. Ili ndi liwiro lochepa kwambiri. Ngati kuyenda kwa ma electron aulere kuli pang'onopang'ono kwambiri, n'chifukwa chiyani nyali yamagetsi imayatsidwa nthawi yomweyo switch ikayatsidwa?
Kuti timvetse izi, ma elekitironi amayenda mu kondakitala ngati momwe madzi amayendera mkati mwa payipi. Ngati payipi yadzaza ndi madzi ndiye kuti ngati mbali imodzi ya payipi yalumikizidwa ku pompo, madziwo amatuluka nthawi yomweyo kuchokera kumapeto kwa payipi ina. Momwemonso, pali ma elekitironi aulere mu waya wamkuwa ndi waya wa babu. Pamene switch yayatsidwa, mphamvu yamagetsi imabuka ndi liwiro loyandikira liwiro la kuwala (liwiro la kuwala = 3 x 10 8 mita/sekondi), zomwe zimapangitsa ma elekitironi aulere kuyamba kuyenda pamodzi panthawiyo. Pali kale ma elekitironi aulere mu waya wa babu kotero kuti kuwala kumakhala koyatsa nthawi yomweyo.
Mavuto ndi mayankho
1. Mphamvu yokhazikika ya 10 A imakhalapo mu waya kwa mphindi ziwiri. Kuchuluka kwa mphamvu yomwe imadutsa kudzera mu kondakitala pamalo aliwonse.
Zodziwika:
Mphamvu yamagetsi (I) = 10 A
Nthawi yopuma (t) = mphindi ziwiri = masekondi awiri x 60 = masekondi 120
Akufuna: Kulipiritsa (Q)
Yankho:
Kuyerekeza kwa mphamvu yamagetsi:
Ine = q/t
I = mphamvu yamagetsi, q = mphamvu yamagetsi, t = nthawi yopuma
Mphamvu yamagetsi:
Q = It = (10)(120) = 1200 C
2. 60 C ya chaji imadutsa pa mfundo mu dera kwa mphindi 5. Kodi mphamvu yamagetsi ndi chiyani?
Zodziwika:
Nthawi yopuma (t) = mphindi 5 = masekondi 5 x 60 = masekondi 300
Mphamvu yamagetsi (Q) = 60 C
Kufunidwa: Mphamvu yamagetsi (I)
Yankho:
Mphamvu yamagetsi:
Ine = Q/t
Ine = 60/300
I = 0.2 Coulombs/sekondi
I = 0.2 Ampere
3. Gawo la mphamvu yamagetsi mu dongosolo la SI ndi…
Anakonza
Coulombs/sekondi
Coulombs/masekondi, opatsidwa dzina lapadera, Ampere.
