Cov Lus Nug Piv Txwv Sib Tham Txog Kev Tiv Thaiv Ohmic thiab Non-Ohmic
Pendahuluuan
Kev tiv thaiv hauv cov voj voog hluav taws xob yog lub tswv yim tseem ceeb rau kev nkag siab txog electrotechnics thiab electronics. Kev tiv thaiv txiav txim siab tias tam sim no yuav ntws ntau npaum li cas los ntawm ib qho khoom thaum muaj hluav taws xob siv rau nws. Muaj ob hom kev tiv thaiv tseem ceeb uas paub hauv physics: kev tiv thaiv ohmic thiab kev tiv thaiv tsis-ohmic. Tsab xov xwm no yuav muab cov lus piav qhia ntxaws txog ob hom kev tiv thaiv, nrog rau ntau qhov piv txwv teeb meem thiab kev sib tham kom koj nkag siab tob dua.
Kev Tiv Thaiv Ohmic
Kev tiv thaiv Ohmic yog kev tiv thaiv uas ua raws li txoj cai Ohm, uas hais tias qhov tam sim no ntws los ntawm tus neeg xyuas hluav taws xob ntawm ob lub ntsiab lus yog sib npaug ncaj qha rau qhov hluav taws xob ntawm ob lub ntsiab lus ntawd. Hauv lej, txoj cai no tuaj yeem sau ua:
"` lej
V = IR
“
Qhov twg:
- V yog qhov hluav taws xob (Volts)
- Kuv yog tam sim no (Ampere)
- R yog qhov tsis kam (Ohm)
Cov khoom uas muaj ohmic tsis kam feem ntau muaj daim duab ntawm kev sib raug zoo ntawm tam sim no thiab voltage hauv daim ntawv ntawm txoj kab ncaj.
Cov Lus Nug Piv Txwv Txog Kev Tiv Thaiv Ohmic
Lo lus nug 1: Ib lub resistor nrog qhov tsis kam ntawm 10 Ohms txuas nrog lub zog hluav taws xob ntawm 5 Volts. Xam qhov tam sim no ntws los ntawm lub resistor.
Kev Sib Tham:
Siv txoj cai Ohm:
\[ V = IR \]
Nws paub tias:
– V = 5 Volt
– R = 10 Ohm
Yog li ntawd:
\[ Kuv = \frac{V}{R} = \frac{5}{10} = 0,5 \, \text{Ampere} \]
Yog li, tam sim no ntws los ntawm lub resistor yog 0,5 Amperes.
Piv Txwv Lo Lus Nug 2 Ohmic Resistance hauv Parallel Circuits
Lo lus nug 2: Ob lub resistors, txhua tus nrog qhov tsis kam ntawm 4 Ohms thiab 6 Ohms, txuas nrog parallel thiab tom qab ntawd txuas nrog 12 Volt voltage qhov chaw. Xam tag nrho cov tam sim no ntws hauv lub voj voog.
Kev Sib Tham:
Hauv ib lub voj voog sib luag, qhov voltage hla txhua lub resistor yog tib yam:
– V = 12 Volt
Yuav kom tau tag nrho cov tam sim no, peb yuav tsum xub nrhiav cov tam sim no hauv txhua lub resistor siv Ohm txoj cai, tom qab ntawd ntxiv lawv ua ke.
1. Tam sim no hauv 4 Ohm resistor:
\[ I_1 = \frac{V}{R_1} = \frac{12}{4} = 3 \, \text{Ampere} \]
2. Tam sim no hauv 6 Ohm resistor:
\[ I_2 = \frac{V}{R_2} = \frac{12}{6} = 2 \, \text{Ampere} \]
Tag nrho cov tam sim no hauv lub voj voog yog:
\[ Kuv_{total} = I_1 + I_2 = 3 + 2 = 5 \, \text{Ampere} \]
Yog li, tag nrho cov tam sim no ntws hauv lub voj voog yog 5 Amperes.
Kev Tiv Thaiv Tsis-Ohmic
Kev tiv thaiv tsis yog-ohmic yog kev tiv thaiv uas tsis ua raws li Ohm txoj cai. Hauv cov khoom uas muaj kev tiv thaiv tsis yog-ohmic, kev sib raug zoo ntawm voltage thiab tam sim no tsis yog linear thiab tej zaum yuav nyob ntawm ntau lwm yam xws li kub, zaus, lossis lub zog hluav taws xob. Qee qhov piv txwv yog cov teeb incandescent, diodes, thiab transistors.
Cov Lus Nug Piv Txwv Txog Kev Tiv Thaiv Tsis Yog-Ohmic
Lo lus nug 3: Ib lub diode zoo tagnrho txuas nrog lub zog hluav taws xob pem hauv ntej ntawm 0.7 Volts. Yog tias qhov tsis kam ntawm lub diode zoo tagnrho raug suav hais tias me me heev, tam sim no yuav ntws li cas thaum lub zog hluav taws xob no raug siv?
Kev Sib Tham:
Hauv ib lub diode zoo tagnrho, thaum tig mus rau pem hauv ntej, lub diode yuav tso cai rau tam sim no ntws nrog qhov tsis kam me me. Yog li ntawd, tam sim no ntws yog txiav txim siab los ntawm nws qhov tsis kam, uas yog zero. Hauv qhov xwm txheej zoo tagnrho, qhov tsis kam no me me heev uas tam sim no tsuas yog txwv los ntawm lub peev xwm ntawm qhov chaw hluav taws xob.
Vim tias lub diode zoo tagnrho, qhov tam sim no tuaj yeem loj heev, ze rau lub capacitance ntawm qhov chaw voltage thiab lub circuit cuam tshuam txuas nrog nws. Txawm li cas los xij, hauv kev siv ua haujlwm, qhov tsis kam ntawm lwm lub circuits thiab cov kev txwv capacitance ntawm qhov chaw voltage yuav txiav txim siab qhov tam sim no tiag tiag ntau dua.
Yog tias qhov chaw hluav taws xob tuaj yeem muab hluav taws xob tsis muaj qhov txwv, ces qhov tam sim no ntws tuaj yeem xav tias loj heev tab sis qhov tseeb nws tsis tsim nyog yam tsis txiav txim siab qhov txwv tam sim no los ntawm lub peev xwm ntawm qhov chaw.
Piv txwv lus nug 4: Kev tiv thaiv tsis yog-Ohmic hauv cov teeb incandescent
Lo lus nug 4: Lub teeb incandescent muaj cov khoom tsis-ohmic nrog lub nominal voltage ntawm 220 Volts thiab lub zog siv ntawm 100 Watts. Xam qhov tsis kam ntawm lub teeb thaum lub teeb nyob rau raws li lub nominal zog thiab voltage.
Kev Sib Tham:
Nws paub tias:
– V = 220 Volt
– P = 100 Watt
Siv cov qauv fais fab,
\[ P = VI \]
Yog li ntawd, qhov tam sim no uas ntws:
\[ Kuv = \frac{P}{V} = \frac{100}{220} \approx 0.455 \, \text{Ampere} \]
Tom ntej no, siv Ohm txoj cai,
\[ R = \frac{V}{I} = \frac{220}{0.455} \approx 484 \, \text{Ohm} \]
Yog li, qhov tsis kam ntawm lub teeb incandescent thaum teeb nrog lub zog nominal thiab voltage yog nyob ib ncig ntawm 484 ohms.
Xaus
Kev nkag siab txog qhov sib txawv ntawm ohmic thiab non-ohmic resistance yog qhov tseem ceeb hauv kev tshuaj xyuas hluav taws xob. Ohmic resistance ua raws li Ohm txoj cai, nrog rau kev sib raug zoo ntawm voltage thiab tam sim no, thaum non-ohmic resistance yog non-linear thiab tuaj yeem cuam tshuam los ntawm ntau lwm yam. Nrog rau ntau yam piv txwv thiab kev sib tham uas tau nthuav tawm saum toj no, peb tuaj yeem nkag siab zoo dua tias ob hom kev tiv thaiv no ua haujlwm li cas thiab yuav ua li cas xam tam sim no, voltage, thiab resistance hauv hluav taws xob.
Kev paub txog ohmic thiab non-ohmic resistance muaj txiaj ntsig zoo heev, tshwj xeeb tshaj yog rau cov neeg ua haujlwm hauv kev tsim hluav taws xob lossis electronics, vim nws pab tsim thiab tshuaj xyuas cov circuits kom zoo dua thiab ua haujlwm tau zoo.
