Yuav ua li cas yog lub dielectric qhov ntawm qhov nruab nrab

Thaum tseem nyob rau hauv lub tsev kawm ntawv ntawm ib zaj lus qhia physics xib fwb, sib tham txog hluav taws xob tshwm sim, piav dab tsi lub dielectric qhov ntawm qhov nruab nrab. Nyob rau hauv lub neej yav tom ntej, yog tias lub ntsiab profession yog tsis muaj feem xyuam rau hluav taws xob engineering, lub ntsiab lus twb tsis nco qab lawm yam xyuam xim. Nyob rau hauv daim ntawv no, peb rov qab zoo li cas cov lus dag qab no txhais.

Feem ntau, rau ib tug piav qhia ntawm lub sij hawm "dielectric qhov ntawm qhov nruab nrab" yog feem ntau yog ib qho piv txwv ntawm ib tug capacitor uas nws phiaj no yuav tiaj tus. Sawv cev rau lub nyuaj capacitor nyob rau hauv vacuo. Txiav txim seb tus nqi ntawm hluav taws xob xwb :

Qv = (U * S * Tsev) / d,

qhov twg d - kev ncua deb ntawm cov phiaj, U - voltage, S - cheeb tsam ntawm lub phaj, Ev - dielectric. qhov. Cov yav tas yog ib tug siv tus nqi, nws yog ib lub dielectric qhov ntawm qhov nruab nrab tsis muaj cua (nqus) thiab yog sib npaug zos rau 8.85 * 10 -12 Farad degree ib 'meter'.

Tab sis capacitors nkauj nraug phaj nruab nrab tej zaum yuav tsis tau tsuas yog ib lub tshuab nqus, tab sis muaj lwm yam dielectric khoom. Obviously, nyob rau hauv rooj plaub no tus dielectric qhov ntawm qhov nruab nrab yog txawv los ntawm «Tsev», yog li ntawd, tus nqi nws txawv. Yog hais tias lub capacitor yog kev cob cog rua rau ib qhov chaw ntawm electromotive quab yuam, tus nqi ntawm tus nqi rau cov phiaj yuav Qz. Lub dielectric qhov ntawm cov ntaub ntawv uas yog tus piv ntawm tus nqi Qz condenser daim hlau txuas rau tus nqi nyob rau hauv cov ntaub ntawv ntawm lub tshuab nqus tsev Qv, i.e.

E = Qz / Qv.

Kom meej meej, qhov dimension yog tsis tuaj kawm ntawv. Powered condenser yuav siv sij hawm hwj chim ntawm lub qhov chaw.

Nyob rau hauv qhov tseeb, nws yog tus kwv tij dielectric qhov ntawm qhov nruab nrab. Nws qhia tau hais tias yuav ua li cas muaj ntau zaus cov kev siv txo xwb sis sib cais los ntawm ib tug dielectric, raws li muab piv nrog daim hlau nyob rau hauv vacuo. Koj yuav tau hais tias qhov no yog ib tug ntawm cov yam ntxwv ntawm cov khoom.

Yog hais tias lub hnab khib xwb rau cov phiaj ntawm lub hwj chim mov yog nres, muaj yog ib tug txawv phenomenon. Xa me nyuam rov voltage, thiab thiaj li, txo qhov hluav taws xob field siv. Yog vim li cas?

Tej ntaub ntawv uas muaj atoms nrog electrons orbiting lub nuclei. Thaum lub electric teb faib tshwm sim nyob rau hauv txhua cov cab kuj molecule ntawm lub polarity ntawm cov sab nraud txiav txim - ib tug thiaj li hu ua polarization txoj kev dipole. Qhov no e-mail nws tsos. Cov khoom nws tus kheej tej zaum yuav muaj xws li ncov qaumteb qabteb thiab nonpolar molecules. Nyob rau hauv rooj plaub thawj lub molecule no yog qhia raws li lub teb (voltage), raws li zoo raws li dipoles caster, tus kwv tij permittivity yog theej siab. Tus nqi ntawm cov permeability yog feem ntau ntau tshaj li 100 units. Nyob rau hauv lub thib ob cov ntaub ntawv (non-polar molecules), txawm hais tias vim qhov kev txiav txim teb thiab lub dipoles raug tsim, ib feem ntawm lub zog siv kom lawv cov spatial configuration, txawm li cas los tsis tseem ceeb txaus permeability thiab tsuj tsawg tshaj 5 units. Nws yuav tsum tau muab sau tseg tias gaseous tshuaj yeej ib txwm muaj ib tug uas tsis muaj permeability vim muaj ib tug me me muaj pes tsawg tus ntawm molecules ib chav tsev ntim, tsis hais ntawm lawv tej yam ntuj tso qauv.

Rau feem ntau ntau dielectric ntaub ntawv permeability cov ntaub ntawv yuav muab nyob rau hauv lub duas paub ntxhuav, ces thaum ua tau zoo rau suav muaj tsis muaj teeb meem nrog lub ntsiab txhais ntawm yam muaj nuj nqis. Interestingly, cov huab cua muaj ib tug permeability ntawm 1 unit. Qhov no piav qhia yog vim li cas nyob rau hauv lub capacitors siv txawv ntxiv dielectric txheej -. Ceramics, mica, paraffin, etc. Tag nrho cov ntaub ntawv, muaj ib tug ntau dua permeability, ua rau kom tus nqi ntawm cov sau xwb rau cov phiaj. Nyob rau hauv lwm yam lus, lub capacitance yuav tau tom tsis tau tsuas yog nyob rau hauv txoj kev cov phiaj qhov chaw, tab sis cais lawv cov duab. Champions cov tshuaj uas muaj permeability yog ceramics (80) thiab ib tug lim dej ntawm impurities (yam tsawg kawg 81).