physics

Tsab xov xwm hais txog Resistivity

Hais txog qhov hluav taws xob tam sim no, qhov ceev ntawm qhov hluav taws xob tam sim no tau tham txog lawm, yog li ntawd kuj tau piav qhia txog lub zog hluav taws xob hauv lub ncauj lus txog lub zog hluav taws xob. Lub zog hluav taws xob thiab lub zog hluav taws xob nyob hauv tus neeg coj hluav taws xob yog tias muaj qhov sib txawv ntawm lub zog hauv tus neeg coj hluav taws xob, thaum yog tias tsis muaj qhov sib txawv ntawm lub zog, ces kuj tsis muaj lub zog hluav taws xob thiab lub zog hluav taws xob.

Hauv yuav luag txhua tus hlau conductors, lub teb hluav taws xob yog ncaj qha proportional rau qhov ceev ntawm lub hluav taws xob tam sim no, qhov twg qhov piv ntawm lub teb hluav taws xob rau qhov ceev ntawm lub hluav taws xob tam sim no yog tas li. Tus nqi ntawm kev sib piv ntawm lub teb hluav taws xob rau qhov ceev tam sim no hu ua resistivity. Mathematically, kev sib raug zoo ntawm lub teb hluav taws xob, qhov ceev tam sim no, thiab resistivity yog hais nyob rau hauv equation:

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Tsab xov xwm hais txog Resistor xim code

Tus resistor yog ib qho ntawm lub voj voog hluav taws xob uas ua haujlwm los tswj tus lej ntawm cov hluav taws xob tam sim no. Feem ntau, muaj ob hom resistors, uas yog cov hlau coil resistors thiab cov carbon resistors. Cov hlau dov resistors feem ntau yog siv hauv chav kuaj, ua los ntawm kev qhwv cov hlau zoo rau ntawm qhov chaw ntawm lub raj insulator. Cov carbon resistors feem ntau yog siv hauv cov voj voog hluav taws xob, cylindrical, thiab muaj cov xov hlau ntawm ob qho kawg. Tus nqi ntawm cov carbon resistor tsis kam yog qhia hauv cov xim code thiab tso tawm rau ntawm qhov chaw ntawm lub resistor.

Tus nqi tsis kam ntawm lub resistor tuaj yeem paub los ntawm kev txhais cov xim code ntawm lub resistor. Yuav kom nkag siab qhov no, ua ntej saib cov lus hauv qab no, tom qab ntawd kawm qhov teeb meem piv txwv los txiav txim siab tus nqi tsis kam ntawm lub resistor.

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Tsab xov xwm hais txog Resistors hauv series

Yog tias cov resistors txuas nrog raws li pom hauv daim duab, cov resistors raug teeb tsa ua series. Resistor lossis hluav taws xob tsis kam hauv nqe lus nug tuaj yeem yog nyob rau hauv daim ntawv ntawm cov khoom resistor, teeb, lossis lwm yam hluav taws xob tsis kam.

Lub zog hluav taws xob txav mus los ntawm qhov tsis kam 1 (R₁) = ua hluav taws xob txav mus los ntawm kev tiv thaiv 2 (R₂) = lub zog hluav taws xob txav mus los ntawm qhov tsis kam 3 (R₃). Hluav taws xob tam sim no (Kuv) yog lub zog hluav taws xob uas ntws thaum lub sijhawm tshwj xeeb (I = Q / t), yog li ntawd lub zog hluav taws xob los ntawm kev tiv thaiv 1 (I₁) = tam sim no hluav taws xob los ntawm kev tiv thaiv 2 (I₂) = tam sim no hluav taws xob los ntawm kev tiv thaiv 3 (I₃). Kev suav lej, tag nrho cov hluav taws xob tam sim no (I) = Kuv₁ = Kuv₂ = Kuv₃.

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Kev sib npaug ntawm kev tiv thaiv hluav taws xob

Hauv zaj lus qhia txog Ohm txoj cai, ib daim qauv uas hais txog kev sib raug zoo ntawm qhov hluav taws xob (V), tam sim no hluav taws xob (I), thiab kev tiv thaiv hluav taws xob (R) tau muab los. Kev suav lej los ntawm cov qauv:

Cov kab zauv no qhia tau hais tias qhov hluav taws xob tsis kam (R) yog sib npaug ncaj qha rau qhov hluav taws xob hluav taws xob (V) thiab sib npaug rau qhov hluav taws xob tam sim no (I). Yog tias qhov hluav taws xob loj dua qhov hluav taws xob tsis kam loj dua, ntawm qhov tsis sib xws, yog tias qhov hluav taws xob muaj zog dua qhov hluav taws xob tsis kam loj dua. Cov kab zauv no piav qhia txog Ohm txoj cai tsuas yog thaum qhov hluav taws xob tsis kam (R) tas li. Yog tias qhov hluav taws xob tsis kam tsis tas li, ces cov kab zauv no tsis piav qhia txog Ohm txoj cai, tab sis piav qhia txog qhov tsis kam ntawm tus neeg coj hluav taws xob.

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Tsab xov xwm hais txog cov Resistors hauv parallel

Yog tias cov resistors txuas nrog zoo li hauv daim duab, cov resistors txuas nrog parallel.

Cov hluav taws xob (cov hluav taws xob = cov nqi hluav taws xob uas ntws thaum lub sijhawm) uas nkag mus rau qhov chaw sib tshuam yog tib yam li cov hluav taws xob tawm ntawm qhov chaw sib tshuam. Muaj ntau qhov sib tshuam yog li tag nrho cov hluav taws xob = qhov ntau ntawm cov hluav taws xob ntws hauv txhua qhov sib tshuam. Kev suav lej, Kuv = Kuv ₁ + Kuv ₂ + Kuv _3. Thaum qhov sib txawv ntawm lub zog hluav taws xob lossis hluav taws xob hauv txhua qhov sib tshuam yog tib yam.

Kuv = V/R yog li cov kab zauv saum toj no hloov mus rau Kuv = V/R ₁ + V/R ₂ + V/R _3. Lub zog hluav taws xob sib npaug, yog li cov kab zauv no hloov mus rau Kuv = V (1/R ₁ + 1/R ₂ + 1/R ₃ ). Yog tias qhov sib npaug tsis kam yog 1/R ces kuv = V (1/R). Yog li, 1/R = 1/R ₁ + 1/R ₂ + 1/R ₃.

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Tsab xov xwm hais txog Qhov chaw ntawm electromotive force emf Internal resistance Terminal voltage

Cov hluav taws xob ntws hauv lub voj voog kaw, los ntawm lub zog siab mus rau lub zog qis. Thaum cov hluav taws xob txav mus los ntawm ib feem ntawm kev tiv thaiv hluav taws xob, muaj kev txo qis ntawm lub zog hluav taws xob vim tias lub zog hluav taws xob siv rau qhov kev tiv thaiv no. Yuav kom cov hluav taws xob txuas ntxiv mus los ntawm lub zog siab mus rau lub zog qis,

Yuav tsum muaj ib lub cuab yeej los ntxiv lub zog hluav taws xob, lub cuab yeej yog lub zog electromotive (emf) lossis qhov tseeb dua hu ua qhov chaw hluav taws xob. Emf lossis qhov chaw hluav taws xob yog ib qho khoom siv uas hloov ib hom zog mus rau hauv lub zog hluav taws xob, xws li roj teeb, lub hnub ci hlwb, lossis cov tshuab hluav taws xob.

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EMFs nyob rau hauv series thiab parallel

Yog tias muaj ob lossis ntau qhov chaw ntawm electromotive (emf) txuas nrog raws li pom hauv daim duab, emf raug teeb tsa ua series.

Qhov sib npaug ntawm qhov hluav taws xob (ε) yog:

ε = ε ₁ + ε ₂ + ε _n

Qhov sib npaug sab hauv tsis kam (r) yog:

r = _r1 + _r2 + _rn

Lub zog hluav taws xob ntws los ntawm sab nraud tsis kam (R) yog:

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Txoj cai thawj zaug ntawm Kirchhoff, uas tseem hu ua txoj cai ntawm qhov chaw sib tshuam, hais tias cov hluav taws xob uas nkag mus rau hauv qhov chaw sib tshuam yog tib yam li cov hluav taws xob tawm ntawm qhov chaw sib tshuam ntawd. Qhov chaw sib tshuam hauv lub voj voog hluav taws xob yog qhov chaw uas ob lossis ntau dua ntawm ob lub xov hlau sib ntsib, xws li qhov chaw a hauv daim duab ntawm sab.

Kuv yog cov hluav taws xob uas nkag mus rau hauv qhov chaw sib tshuam, thaum kuv ₁ thiab kuv ₂ yog cov hluav taws xob uas tawm ntawm qhov chaw sib tshuam, kuv = kuv ₁ + kuv _2. Lwm qhov piv txwv, saib daim duab hauv qab no.

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Txoj cai thib ob ntawm Kirchhoff hais tias qhov kev hloov pauv ntawm lub zog hluav taws xob ntawm qhov ncig ntawm lub voj voog kaw yog xoom. Txoj cai thib ob ntawm Kirchhoff yog raws li txoj cai ntawm kev txuag lub zog, uas hais tias lub zog yog nyob mus ib txhis.

Yuav kom nkag siab zoo dua qhov no, xav txog lub zog hluav taws xob txav mus rau hauv lub voj voog kaw, zoo li hauv daim duab. Thaum lub zog hluav taws xob hla dhau ib qho hluav taws xob tsis kam (R), tus lub zog hluav taws xob raug txo vim nws siv rau cov kev tiv thaiv no. Yog tias lub zog hluav taws xob hla dhau lwm qhov kev tiv thaiv hluav taws xob, lub zog hluav taws xob muaj peev xwm txo qis dua vim nws siv dua rau ntawm qhov tsis kam. Ntxiv mus, thaum lub zog hluav taws xob hla dhau qhov chaw hluav taws xob los ntawm qhov muaj peev xwm qis mus rau qhov muaj peev xwm siab, lub zog hluav taws xob muaj peev xwm nce ntxiv. Thaum nws rov qab mus rau nws qhov chaw qub, lub zog hluav taws xob muaj peev xwm zoo ib yam li yav dhau los, qhov twg qhov kev hloov pauv ntawm lub zog hluav taws xob muaj peev xwm yog xoom. Thaum thov KirchhoffTxoj cai thib ob rau lub voj voog hluav taws xob, peb siv qhov kev hloov pauv ntawm qhov hluav taws xob, tsis yog qhov kev hloov pauv ntawm lub zog hluav taws xob.

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Kev txhais ntawm lub zog hluav taws xob

Lub zog uas kawm tau hauv txoj haujlwm thiab Lub Zog yog txiav txim siab ua txoj haujlwm ua tiav thaum lub sijhawm tshwj xeeb. Kev ua haujlwm yog ib qho txheej txheem ntawm kev hloov pauv lub zog kom lub zog tuaj yeem nkag siab tias yog kev hloov pauv ntawm lub zog uas tshwm sim thaum lub sijhawm tshwj xeeb.

Lub zog hluav taws xob yog kev hloov pauv ntawm lub zog hluav taws xob thaum lub sijhawm tshwj xeeb. Hauv kev tshuaj xyuas txog lub zog hluav taws xob, nws piav qhia tias kev hloov pauv ntawm lub zog hluav taws xob tshwm sim thaum lub zog hluav taws xob hla dhau qhov sib txawv ntawm lub zog hluav taws xob.

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