Kahua Magnetic a puni ke au uila
Pengantar
He hanana kūlohelohe kahi kahua makeneti e kū nei a puni kahi au uila. Ke kahe ka au uila ma o kahi alakaʻi, hoʻokumu ʻia kahi kahua makeneti a puni ia. Ua ʻike mua ʻia kēia hanana e Hans Christian Ørsted i ka makahiki 1820. Ua ʻike ʻo Ørsted ua hoʻohuli ʻia kahi nila panana i ka wā e kau ʻia ai ma kahi kokoke i kahi uea e lawe ana i ke au, e hōʻike ana i ke alo o kahi kahua makeneti a puni ka uea. Ua hoʻomākaukau kēia ʻike i ke ala no ka hoʻomohala ʻana o ka electromagnetism, ke kumu o ka ʻenehana hou.
Kumumanaʻo Kumu
Hiki ke wehewehe ʻia ke kahua makeneka i hana ʻia e ke au uila e ke kānāwai Biot-Savart a me ke kānāwai o Ampère. ʻŌlelo ke kānāwai Biot-Savart ua hana ʻia kahi kahua makeneka e kahi mea liʻiliʻi o ke au uila. Ma ke ʻano makemakika, ua hōʻike ʻia kēia kānāwai penei:
\[ \mathbf{dB} = \frac{\mu_0}{4\pi} \frac{I \mathbf{dl} \times \mathbf{\hat{r}}}{r^2} \]
Ma hea:
– ʻO \(\mathbf{dB}\) ke kahua makeneka i hana ʻia e ka mea au uila \(\mathbf{dl}\),
– ʻo \(\mu_0\) ka permeability vacuum,
– ʻO \(I\) ke au uila,
– ʻO \(\mathbf{\hat{r}}\) he vector unit e kuhikuhi ana mai ka element o kēia manawa a i ke kiko nānā,
– ʻO \(r\) ka mamao ma waena o ka element o kēia manawa a me ke kiko nānā.
ʻO ke kānāwai o Ampère, ma ka ʻaoʻao ʻē aʻe, ʻōlelo ʻo ke kahua magnetic e kaʻapuni ana a puni kahi loop pani ʻia e like me ke au uila e kahe ana ma o kēlā loop. Ma ke ʻano makemakika, ua hōʻike ʻia kēia kānāwai penei:
\[ \oint \mathbf{B} \cdot d\mathbf{l} = \mu_0 I_{\text{encl}} \]
Ma hea:
– ʻo \(\mathbf{B}\) ke kahua makeneka,
– \(d\mathbf{l}\) he mea ala,
– ʻO \(I_{\text{encl}}\) ke au uila i hoʻopuni ʻia e kahi ala pani.
Kahua Magnetic a puni ka Uea Pololei
No kahi uea pololei e lawe ana i kahi au uila, hiki ke helu ʻia ke kahua makeneka hopena me ka hoʻohana ʻana i ke kānāwai Biot-Savart. Ma kahi mamao \(r\) mai ke uea, ʻo ka nui o ke kahua makeneka \(B\) he:
\[ B = \frac{\mu_0 I}{2\pi r} \]
Aia kēia kahua makeneti ma ke ʻano o kahi pōʻai e hoʻopuni ana i ke kaula me ke kuhikuhi i hoʻoholo ʻia e ka lula lima ʻākau: inā kuhikuhi ka manamana nui o ka lima ʻākau i ke kuhikuhi o ke au uila, a laila hōʻike nā manamana lima e hoʻopuni ana i ke kuhikuhi o ke kahua makeneti.
Kahua Magnetic a puni kahi Solenoid
He wili uea lōʻihi ka solenoid me nā huli he nui. Ke kahe ke au uila ma o ka solenoid, hana ʻia kahi kahua magnetic ikaika a like i loko o ka solenoid. He nāwaliwali loa ke kahua magnetic ma waho o ka solenoid a hiki ke manaʻo ʻia he mea ʻole. Hiki ke helu ʻia ka nui o ke kahua magnetic i loko o kahi solenoid kūpono me ka hoʻohana ʻana i:
\[ B = \mu_0 n I \]
Ma hea:
– ʻO \(n\) ka helu o nā huli no kēlā me kēia lōʻihi o ka solenoid,
– ʻO \(I\) ke au uila e kahe ana ma o ka solenoid.
Ka Hoʻohana ʻana o ke Kahua Magnetic mai ke Au Uila
1. Nā Motika Uila a me nā Mea Hana Hana
Hana nā motika uila ma ke kumumanaʻo e hana ana kahi au uila e kahe ana ma o kahi kahua magnetic i kahi ikaika. I ka ʻaoʻao ʻē aʻe, hana nā mea hana ma ka hoʻoulu ʻana i kahi au uila ke neʻe kahi alakaʻi ma o kahi kahua magnetic. Hoʻohana nā mea ʻelua i ke kahua magnetic i hana ʻia e kahi au uila e hoʻololi i ka ikehu uila i ikehu mechanical, a i ʻole ka ʻaoʻao ʻē aʻe.
2. Mea hoʻololi
Hoʻohana ʻia nā mea hoʻololi uila e hoʻonui a hoʻemi paha i ke ana uila i loko o kahi ʻōnaehana hoʻolaha uila. Hana nā mea hoʻololi uila ma ke kumumanaʻo o ka hoʻokomo electromagnetic, kahi e hoʻoulu ai kahi kahua magnetic e loli nei i hana ʻia e ke au uila i loko o ka wili mua i kahi au uila i loko o ka wili lua.
3. Hoʻokomo Uila
Ua ʻike ʻia ke ʻano o ka hoʻokomo electromagnetic e Michael Faraday, nāna i ʻōlelo e hiki i kahi kahua magnetic e loli nei ke hoʻoulu i kahi au uila i loko o kahi alakaʻi. Hoʻohana ʻia kēia kumumanaʻo i nā noi like ʻole e like me nā mea ʻike metala, nā microphone, a me nā mea ʻike like ʻole.
Noiʻi a me ka Hoʻomohala Holomua
Ke hoʻomau nei ka noiʻi ʻana i nā kahua magnetic a me nā au uila me ka holomua o ka ʻenehana. ʻO kekahi mau wahi noiʻi hoihoi:
1. Nā Superconductors
ʻO nā superconductors he mau mea hiki ke hoʻokele i ka uila me ke kūʻē ʻole i nā mahana haʻahaʻa loa. Hōʻike ke kahua magnetic a puni kahi superconductor i nā waiwai kūikawā, e like me ka hopena Meissner, kahi e wehe ʻia ai ke kahua magnetic mai ka mea superconducting. ʻO ka pahuhopu o ka noiʻi ma kēia kahua e hoʻomohala i nā superconductors wela kiʻekiʻe e hiki ke hana i nā mahana kūpono.
2. Nā Wai Magnetorheological a me Electrorheological
ʻO nā wai Magnetorheological (MR) a me electrorheological (ER) he mau wai ia e hiki ke hoʻololi ʻia ko lākou mānoanoa ma o ka hoʻopili ʻana i kahi kahua magnetic a uila paha. Hoʻohana ʻia kēia mau wai i nā noi like ʻole e like me ka damping vibration a me nā couplings akamai. Ke hoʻomau nei ka noiʻi e hoʻomaikaʻi i ka hana a me ke kūpaʻa o kēia mau wai.
3. Nā Mea Ferromagnetic a me ka Nanotechnology
Loaʻa i nā mea Ferromagnetic ka magnetization ikaika a hoʻohana ʻia i nā ʻano mea like ʻole e like me ka hoʻomanaʻo magnetic a me nā sensor. Me nā holomua i ka nanotechnology, hiki ke hana ʻia nā mea ferromagnetic ma ka pālākiō nanometer e hoʻomaikaʻi i kā lākou hana a me ka pono i nā mea uila.
Ka hopena
ʻO ke kahua magnetic e hoʻopuni ana i ke au uila he hanana koʻikoʻi ia i ka physics nona nā noi he nui i ke ola o kēlā me kēia lā a me ka ʻenehana hou. ʻO ka hoʻomaopopo ʻana i kēia mau kahua magnetic e hiki ai iā mākou ke hoʻomohala i nā mea hana e like me nā mīkini uila, nā mea hana, a me nā mea hoʻololi, he mea nui ia i nā ʻōnaehana hoʻolaha uila a me nā mea uila. Ke hoʻomau nei ka noiʻi ma kēia wahi i ka holomua, e wehe ana i nā manawa hou i ka ʻenehana superconducting, nā wai akamai, a me nā mea ferromagnetic. Me ka hoʻomaopopo hohonu ʻana i nā kahua magnetic a me nā au uila, hiki iā mākou ke hoʻomau i ka hoʻomohala ʻana i nā ʻenehana ʻoi aku ka maikaʻi a me ka hou no ka wā e hiki mai ana.
