Kumvetsetsa Lamulo la Ohm
Komanso phunzirani nkhani zokhudza mafunso a chitsanzo cha lamulo la Ohm ndi kukambirana za mafunso a lamulo la Ohm.
Pafupifupi makina onse oyendetsera zitsulo, munda wamagetsi molingana ndi kuchuluka kwa magetsi, komwe chiŵerengero cha mphamvu yamagetsi ku mphamvu yamagetsi chimakhala chokhazikika. Kufotokozedwa mwa masamu kudzera mu equation:
ρ = E / J
Kufotokozera: E = mphamvu yamagetsi, ρ = mphamvu yotsutsa, J = mphamvu yamagetsi.
Chiyerekezo chokhazikika ρ chimatchedwa kukana kwapadera kapena kukana, komwe mtengo wake ndi wokhazikika ndipo sikudalira mphamvu yamagetsi yomwe imapanga magetsi.
Ngati magetsi akuwonjezeka, mphamvu yamagetsi ikuwonjezekanso, mosiyana, ngati magetsi akuchepa, mphamvu yamagetsi ikuchepanso, kotero kuti chiŵerengero cha mphamvu yamagetsi ku mphamvu yamagetsi chikhale chokhazikika. Ichi ndi chiganizo cha lamulo la Ohm . Chifukwa chake equation yomwe ili pamwambapa ikufotokoza lamulo la Ohm pokhapokha ngati ρ ndi yokhazikika komanso yodziyimira payokha pa mphamvu yamagetsi. Lamulo la Ohm siligwira ntchito ngati mtengo wa ρ usintha pamene mphamvu yamagetsi ikusintha.
Komabe, ndikosavuta kuyeza mphamvu yamagetsi (V) kuposa mphamvu yamagetsi (E), komanso ndikosavuta kuyeza mphamvu yamagetsi (I) kuposa mphamvu yamagetsi (J). Chifukwa chake, kupatula kufotokozedwa m'mawu amagetsi , mphamvu yamagetsi ndi kukana (ρ), lamulo la Ohm limafotokozedwanso m'mawu a mphamvu yamagetsi , mphamvu yamagetsi ndi kukana kwamagetsi (R).
Choyamba, taganizirani za waya woyendetsa magetsi womwe uli ndi kutalika (l), dera lopingasa (A) ndipo pali kusiyana kwa mphamvu yamagetsi (V) pakati pa malekezero awiri a waya. Ngati mphamvu yamagetsi ndi yofanana, kapena kuti yofanana monsemo, ndiye kuti ubale pakati pa mphamvu yamagetsi ndi kusiyana kwa mphamvu yamagetsi umafotokozedwa mu equation V = E s ( equation iyi yafotokozedwa mu zinthu zamagetsi ). Ngati mphamvu yamagetsi ndi yofanana, kapena kuti yofanana monsemo, ndiye kuti ubale pakati pa mphamvu yamagetsi ndi mphamvu yamagetsi umafotokozedwa mu equation I = JA ( equation iyi yafotokozedwa mu zinthu zamagetsi ).
Kuti mupeze equation yomwe imafotokoza ubale pakati pa mphamvu yamagetsi (V), mphamvu yamagetsi (I) ndi kukana kwamagetsi (R), m'malo mwa E ndi J mu equation yotsutsa ndi E mu equation yamphamvu yamagetsi ndi J mu equation yamagetsi yamagetsi:
Iyi ndi equation yomwe imafotokoza ubale womwe ulipo pakati pa mphamvu yamagetsi (V), mphamvu yamagetsi (I) ndi kukana kwamagetsi (R) mu kondakitala. Kutengera equation iyi, zitha kunenedwa kuti kukana kwamagetsi mu kondakitala ndi chiŵerengero cha kusiyana kwa mphamvu yamagetsi ndi mphamvu yamagetsi mu kondakitala.
Lamulo la Ohm limati chiŵerengero cha kusiyana kwa mphamvu zamagetsi ndi mphamvu zamagetsi ndi chosasintha. Mwa kuyankhula kwina, equation iyi ikufotokoza lamulo la Ohm pokhapokha ngati kukana kwamagetsi (R) kuli kosasintha. Lamulo la Ohm siligwira ntchito ngati kukana kwamagetsi sikuli kosasintha, mwachitsanzo, kumasinthasintha.
Potengera equation yomwe ili pamwambapa, kukana kwamagetsi (R) kwa kondakitala kumakhudzananso ndi kukana kwapadera (ρ), kutalika kwa kondakitala (l) ndi dera lopingasa (A) la kondakitala. Mwa masamu, izi zafotokozedwa mu equation:
Equation iyi ikufotokozedwa mwatsatanetsatane mu nkhani yokhudza kukana kwamagetsi.
Fomula ya Malamulo a Ohm
Lamulo la Ohm limafotokozedwa ndi ma equation awiri, omwe ndi ρ = E/J ndi R = V/I. Tiyenera kudziwa kuti ma equation awiriwa ndi ma equation a lamulo la Ohm pokhapokha ngati ρ ndi yokhazikika ndipo R ndi yokhazikika. Ngati ρ ndi R za conductor zisintha, ma equation awiriwa safotokoza lamulo la Ohm, koma ρ = E/J amafotokoza kukana kwapadera kwa conductor ndipo R = V/I amafotokoza kukana kwamagetsi kwa conductor.
Equation ρ = E/J ikhoza kulembedwa ngati E = ρ J. Pamene ρ ndi yosasintha ndiye kuti E imakhala yofanana ndi J, kutanthauza kuti ngati E ikuwonjezeka ndiye kuti J ikuwonjezeka kapena ngati E ikuchepa ndiye kuti J ikuchepa.
Mofananamo, equation R = V/I ikhoza kulembedwa ngati V = I R. Pamene R ndi yosasinthika, V imakhala yofanana ndi I, kutanthauza kuti ngati V ikuwonjezeka, ine ndikuwonjezeka, kapena ngati V ikuchepa, ine ndikuchepa.
Zipangizo zomwe zimatsatira lamulo la Ohm zimanenedwa kuti ndi ohmic, pomwe zipangizo zomwe sizitsatira lamulo la Ohm zimanenedwa kuti ndi nonohmic. Pafupifupi ma conductor onse achitsulo ndi ohmic, pomwe zipangizo zina zambiri sizili nonohmic.
Mu zinthu zopanda ohmic, kukana kwa magetsi sikokhazikika, koma kumasiyana malinga ndi kusiyana kwa mphamvu yamagetsi ndi kuthekera. Izi zikutanthauza kuti ngati mphamvu yamagetsi isintha, kukana kwa zinthuzo kumasinthanso, komanso momwemonso, ngati mphamvu yamagetsi isintha, kukana kwa zinthuzo kumasinthanso. Chifukwa kukana kwamagetsi kumasiyana, muzinthu zopanda ohmic, mphamvu yamagetsi (V) siili yofanana mwachindunji ndi mphamvu yamagetsi (I).
Ma graph a V, I ndi R
Mu zinthu za ohmic, chiŵerengero cha V mpaka I chimakhala chokhazikika, choimiridwa ndi mzere wowongoka. Zitsanzo za zinthu za ohmic ndi ma conductor achitsulo. Pakadali pano, mu zinthu zopanda ohmic, chiŵerengero cha V mpaka I sichikhala chokhazikika, choimiridwa ndi mzere wokhota. Zitsanzo za zinthu zopanda ohmic ndi ma semiconductor diodes ndi ma transistors.
Lamulo la Ohm limagwira ntchito pazinthu za ohmic zokha osati pazinthu zonse, kotero sikolondola kulitcha lamulo ngati malamulo a Newton kapena malamulo ena a fizikisi. Malamulo a fizikisi amagwira ntchito pazinthu zonse, osati pazinthu zina zokha. Komabe, kugwiritsa ntchito lamulo la Ohm kwakhala chizolowezi chofala, kotero kumatchedwabe lamulo la Ohm, bola ngati zikukumbukiridwa kuti lamulo la Ohm limagwira ntchito pazinthu za ohmic zokha. Kupatula lamulo la Ohm, chitsanzo china cha malingaliro olakwika omwe anthu ambiri amakumana nawo ndi kugwiritsa ntchito lamulo la mpweya wabwino kapena lamulo la Hooke.
