Ka wehewehe ʻana o ke au uila
I loko o kahi alakaʻi e like me ke keleawe, aia nā electrons e neʻe wale ana ma ka wikiwiki kiʻekiʻe me ka manuahi akā ʻaʻole e pakele mai ka metala. ʻO nā electrons e hiki ke neʻe manuahi ua kapa ʻia ʻo free electrons. ʻOiai ke neʻe manuahi nei nā electrons i nā ʻaoʻao āpau, ʻaʻohe kahe holoʻokoʻa o nā electrons i kahi kuhikuhi kikoʻī. Hana ʻia kēia kūlana ke ʻaʻohe ʻokoʻa hiki ma waena o nā wēlau ʻelua o ke kaula keleawe.
Ke hoʻopili ʻia ke kaula i kahi kumu uila, kū mai kahi ʻokoʻa hiki ma waena o nā wēlau ʻelua o ke kaula keleawe, i ʻike ʻia ai kahi kahua uila i loko o ke kaula keleawe. ʻO ke ola ʻana o kahi kahua uila e hoʻoulu ai i nā electrons manuahi e ʻike i ka ikaika uila F = q E = e E, kahi F = ikaika uila , e = uku uila, E = kahua uila . ʻO kēia ikaika uila ke kumu o nā electrons āpau e neʻe manuahi ana e wikiwiki pū, ʻo ia ke kuhikuhi like me ka ikaika uila.
ʻO nā electrons manuahi e neʻe pū ana ma waena o nā ʻātoma e noho ana i loko o ke kaula keleawe i hiki ai i nā electrons āpau ke kuʻi me nā ʻātoma. ʻO ke kuʻi ʻana ke kumu o ka loli ʻana o ke kuhikuhi o nā electrons manuahi. Loaʻa mau i kēia mau electrons āpau kahi ikaika uila i hiki ai i nā electrons āpau ke hoʻolalelale ʻia i ke kuhikuhi like me ke kuhikuhi o ka ikaika uila. Ma hope o ka neʻe ʻana no kekahi manawa, kuʻi nā electrons manuahi me nā ʻātoma i loko o ke kaula keleawe. Akā ʻike mau nā electrons manuahi i kahi ikaika uila i hiki ai i nā electrons āpau ke hoʻolalelale hou ʻia. No laila, ma waho aʻe o ka neʻe ʻana ma nā ʻaoʻao like ʻole, neʻe mālie pū nā electrons manuahi āpau i ke kuhikuhi o ka ikaika uila a ma ke kuhikuhi ʻē aʻe i ke kahua uila. ʻO ke kuhikuhi o ke kahua uila mai kahi hiki uila kiʻekiʻe a i kahi hiki uila haʻahaʻa, ʻoiai ʻo nā electrons e neʻe mai kahi hiki haʻahaʻa a i kahi hiki kiʻekiʻe. He wikiwiki loa ka neʻe ʻana o kēlā me kēia electrons manuahi, ʻoiai ʻo ka neʻe ʻana me nā electrons manuahi ma ke kuhikuhi o ka ikaika uila he lohi loa. Ua kapa ʻia kēia neʻe ʻana me nā electrons manuahi ma ke kuhikuhi o ka ikaika uila he wikiwiki drift.
Ua wehewehe ʻia ke au uila ʻo ia ke kahe ʻana o ka uku uila ma o kahi ʻāpana kea o kahi alakaʻi i loko o kahi manawa i hoʻākāka ʻia. E like me ka ʻaelike, ʻo ke kuhikuhi o ke au uila ua like ia me ke kuhikuhi o ka uku maikaʻi. Ua hana ʻia kēia ʻaelike ma mua o ka ʻike ʻia ʻana ʻo ka mea e neʻe maoli ana i loko o kahi alakaʻi ʻo ia nā electrons manuahi i hoʻopiʻi maikaʻi ʻole ʻia. ʻO ke kuhikuhi o ka neʻe ʻana o nā electrons i loko o ke alakaʻi he kūʻē i ke kuhikuhi o ke au uila. No laila, inā mākou e kūkākūkā i ke au e kahe ana i loko o ke alakaʻi, ʻo ka mea i manaʻo ʻia ʻo ke kahe o ka uku maikaʻi, i kapa ʻia hoʻi he au kuʻuna no ka mea ʻo ia ka hopena o kahi ʻaelike.
ʻO ke kaulike o ke au uila
Ma ke ʻano makemakika, ua hōʻike ʻia ke au uila e ka hoohalike:
ʻI = ΔQ / Δt
I = ke au uila, ΔQ = ka nui o ka hoʻouku uila, Δt = ka wā manawa.
ʻĀpana o ke au uila
ʻO Coulomb ke anakahi o ka hoʻouku uila, ʻo ke anakahi o ka manawa kekona, no laila ʻo Coulomb/kekona ke anakahi o ke au uila. Ua kapa ʻia ʻo Coulomb/kekona ʻo Ampere, ʻo ia ka inoa o ke kanaka ʻepekema Farani ʻo Andre Marie Ampere (1775-1836). 1 Ampere = 1 Coulomb/kekona (1 A = 1 C/s). I nā huaʻōlelo ʻē aʻe, ua like ke au uila o 1 Ampere me ka hoʻouku uila o 1 Coulomb e hele ana ma kahi ʻāpana ʻāpana o ke kaula no 1 kekona. Ma waho aʻe o ka hōʻike ʻia ʻana ma Amperes, ua hōʻike ʻia hoʻi nā au uila ma milliamperes (1 mA = 10 -3 A), microamperes (1 μA = 10 -6 A), nano amperes (1 nA = 10-9 A) a i ʻole picoamperes (1 pA = 10 -12 A).
Laʻana pilikia 1:
Ke kahe nei ke au o 2 Amperes ma o ke kaula no 8 kekona. E hoʻoholo i ka nui o ka uku e hele ana ma kahi kiko a me ka helu o nā electrons i loko o kēlā uku!
ʻIke ʻia:
Au uila (I) = 1 Ampere
Ka manawa (t) = 2 kekona
Makemake ʻia: ka hoʻouka (Q) a me ka helu o nā electrons (e)
pāʻoihana:
Ka hoʻohālikelike o ke au uila:
ʻO wau = Q/t
I = ke au uila, Q = ka hoʻouku uila, t = ka manawa
Uila uila:
Q = I t = (2 Ampere)(8 kekona) = 16 C.
ʻO ke kumukūʻai o hoʻokahi electron he 1.6 x 10 -19 Coulomb, no laila ua like ka nui o nā electrons o ke kumukūʻai o 16 Coulombs me 16 C / 1.6 x 10 -19 Coulomb = 10 x 10 19 electrons.
Au uila, wikiwiki o ka holo ʻana, a me ka nui o ke au
E nānā hou i ka hoʻouku maikaʻi e neʻe ana i ka ʻākau me ka wikiwiki, e lana ana iā v ma ke kuhikuhi o ke kahua uila E
ma luna o kahi alakaʻi nona ka ʻāpana ʻāpana A. Neʻe ka uku maikaʻi a hiki i ka s = vt i ka wā manawa t.
Inā ʻo ka helu o nā ʻāpana i hoʻopiʻi ʻia no kēlā me kēia leo (ka nui o nā ʻāpana i hoʻopiʻi ʻia) he n a ʻo ka leo o ke alakaʻi he A s = A vt,
a laila ʻo ka helu o nā ʻāpana i hoʻopiʻi ʻia i loko o ka nui o ke alakaʻi he n A v t. Inā loaʻa i kēlā me kēia ʻāpana i hoʻopiʻi ʻia kahi uku o q a laila ʻo ka nui o ka uku e hele ana ma ka hopena o ke alakaʻi i ka wā t ʻo Q = nq A v t. No laila, ʻo ke au uila e kahe ana ma ka piko o ke alakaʻi he I = Q / t = nq A v. ʻOiai ʻo ka nui o ke au a i ʻole ke au no kēlā me kēia ʻāpana ʻāpana A ʻo J = I / A = nq v.
Hiki ke hoʻoholo ʻia ʻo ke au e kahe ana i loko o ke alakaʻi ka huahana o ka hoʻonui ʻia ʻana o ka nui o nā ʻāpana i hoʻopiʻi ʻia (n),
ka nui o ka uku no kēlā me kēia ʻāpana (q), ka ʻāpana o ke alakaʻi (A) a me ka wikiwiki o nā ʻāpana i hoʻopiʻi ʻia (v).
E aʻo i nā nīnau hoʻohālike ma lalo nei.
Laʻana pilikia 2:
Ke kahe nei ke au mau o 10 amperes i loko o kahi uea keleawe me kahi ʻāpana kea o 3 x 10 -6 m² . ʻO ka nui o ka electron manuahi he 8.4 x 1028 electrons /m² . E hoʻoholo i ka wikiwiki o ka holo ʻana o ka electron manuahi!
ʻIke ʻia:
Au uila (I) = 10 Ampere
ʻĀpana ʻāpana uea (A) = 3 x 10 -6 m2
Ka nui o nā electron manuahi (n) = 8.4 x 1028 m -3
Ka uku uila (q) = 1.6 x 10 -19 C
Makemake ʻia: Ka wikiwiki o ka holo ʻana o nā electron manuahi (v)
pāʻoihana:
Ua helu ʻia ka wikiwiki o nā electrons me ka hoʻohana ʻana i kahi formula i loaʻa ma mua:
I = ke au uila, n = ka nui o nā ʻāpana i hoʻopiʻi ʻia = ka nui o ka electron, q = hoʻokahi uku electron, A = ka ʻāpana ʻāpana o ke alakaʻi, v = ka wikiwiki o ka holo ʻana o ka electron
ʻO ka wikiwiki o ka holo ʻana o ka electron he 0.248 x 10 -3 mika/kekona = 0.248 millimeters/kekona.
Neʻe pū nā electrons manuahi i loko o kahi uea i ka wikiwiki o 0.248 millimeters i kekona. I nā huaʻōlelo ʻē aʻe, i kēlā me kēia kekona, neʻe nā electrons manuahi a pau a hiki i ka 0.248 millimeters. He wikiwiki lohi loa kēia. Inā lohi loa ka neʻe ʻana o nā electrons manuahi, no ke aha e hoʻā koke ai ke kukui uila ma hope o ka hoʻā ʻia ʻana o ke kuapo?
No ka hoʻomaopopo ʻana i kēia, kahe nā electrons i loko o ke alakaʻi e like me ke kahe ʻana o ka wai i loko o ka hose. Inā ua piha ka hose i ka wai a laila inā pili kekahi wēlau o ka hose i ka faucet, kahe koke ka wai mai kekahi wēlau o kekahi hose. Pēlā nō, aia nā electrons manuahi i loko o ke kaula keleawe a me ke kaula kukui. Ke hoʻā ʻia ke kuapo, kū mai kahi kahua uila me ka wikiwiki e hoʻokokoke ana i ka wikiwiki o ka mālamalama (ka wikiwiki o ke kukui = 3 x 10 8 mika/kekona), kahi e hoʻomaka ai nā electrons manuahi e neʻe pū i kēlā manawa. Aia nā electrons manuahi i loko o ke kaula kukui i hiki ai ke hoʻā ʻia ke kukui i kēlā manawa.
Nā pilikia a me nā hāʻina
1. Aia ke au paʻa o 10 A i loko o kahi uea no 2 mau minuke. ʻEhia ka nui o ka uku e hele ana ma o ke alakaʻi ma kekahi wahi.
ʻIke ʻia:
Au uila (I) = 10 A
Ka manawa (t) = 2 minuke = 2 x 60 kekona = 120 kekona
Makemake ʻia: Hoʻouka (Q)
Lōlā:
Ka hoʻohālikelike o ke au uila:
ʻO wau = q/t
ʻO I = ke au uila, ʻo q = ka uku uila, ʻo t = ka wā ma waena
ʻO ka uku uila:
Q = ʻIke ʻia = (10)(120) = 1200 C
2. Hele ka 60 C o ka uku uila ma kahi kiko i loko o ke kaapuni no 5 mau minuke. He aha ke au uila?
ʻIke ʻia:
ʻO ka manawa ma waena (t) = 5 mau minuke = 5 x 60 kekona = 300 kekona
ʻO ka uku uila (Q) = 60 C
Makemake ʻia: Ke au uila (I)
Lōlā:
Ke au uila:
ʻO wau = Q/t
I = 60 / 300
ʻO I = 0.2 Coulombs/kekona
ʻO I = 0.2 Amperes
3. ʻO ke anakahi o ke au uila i loko o ka ʻōnaehana SI…
pāʻoihana
Coulombs/kekona
ʻO Coulombs/kekona, i hāʻawi ʻia i kahi inoa kūikawā, ʻo Ampere.
