Tanthauzo la mphamvu yamagetsi
Mphamvu yamagetsi imafotokozedwa ngati mphamvu yamagetsi pa unit charge. Tiyerekeze kuti ikakhala pa point a, charge q ili ndi mphamvu yamagetsi yofanana ndi EP a , ndiye kuti mphamvu yamagetsi pa point a imapangidwa motere:
V = mphamvu yamagetsi, EP = mphamvu yamagetsi, q = mphamvu yamagetsi
V si pa mfundo a yokha komanso pa mfundo zonse zamagetsi . Mfundo a imagwiritsidwa ntchito ngati chitsanzo. Monga momwe tidzafotokozera pambuyo pake, V sidalira mphamvu ya q.
EP ndi mphamvu yamagetsi ndi kuchuluka kwa scalar kotero kuti V imaphatikizaponso kuchuluka kwa scalar. Gawo la dongosolo lapadziko lonse la EP ndi Joule ndipo gawo la dongosolo lapadziko lonse la mphamvu yamagetsi ndi Coulomb kotero kuti gawo la dongosolo lapadziko lonse la V ndi Joule pa Coulomb (J/C). Dzina lina la J/C ndi Volt, lochokera ku dzina la wasayansi waku Italy komanso wopanga batire yamagetsi, Alessandro Volta (1745-1827).
Kusiyana kwa mphamvu zamagetsi
V pamalo monga V pamalo a, mwachitsanzo, V a , sangadziwike chifukwa chofunikira kwambiri ndi kusintha kwa mphamvu zamagetsi. Kusintha kwa mphamvu zamagetsi kumatha kudziwika ndi mtengo wake, kaya kudzera mu kuwerengera kapena muyeso. V imasintha pamene mphamvu q isuntha kuchokera pamalo ena kupita kwina. Tiyerekeze kuti mphamvu q isuntha kuchokera pamalo a kupita pamalo b ndiye kusintha kwa V ndi:
Vab ndi kusiyana kwa V pakati pa mfundo ziwiri mu gawo lamagetsi, mwachitsanzo, mfundo a ndi b. Kusiyana kwa V pakati pa mfundo a ndi b (V ab ) ndi kofanana ndi ntchito yomwe mphamvu yamagetsi imagwirira ntchito mu mphamvu yamagetsi ikasuntha kuchokera pa mfundo a kupita pa mfundo b, pa unit charge (W ab / q). Tiyenera kudziwa kuti ntchito yomwe mphamvu yamagetsi imagwirira ntchito ya mphamvu ya q ikasuntha kuchokera pa mfundo a kupita pa mfundo b (W ab ) ndi yofanana ndi kusintha kwa mphamvu yamagetsi ya mphamvu ya q (ΔEP). Chifukwa chake, mu equation pamwambapa, ΔEP ikhoza kusinthidwa ndi W ab.
Chinthu chikakhala pamalo enaake pamwamba pa nthaka, chimakhala ndi mphamvu yokoka, komwe pamwamba pa nthaka pamagwiritsidwa ntchito ngati malo ofotokozera. Pankhaniyi, kutalika kwa pamwamba pa nthaka ndi mphamvu yokoka pamalo omwe ali pansi zimayikidwa pa zero. Mofanana ndi mphamvu yokoka, tikanena kuti pali mphamvu inayake yamagetsi, iyenera kukhala mfundo ina yogwiritsidwa ntchito ngati malo ofotokozera, poganizira kusiyana kwa mphamvu yamagetsi komwe kungawerengedwe. Nthawi zambiri, ma conductor apansi kapena amagetsi olumikizidwa pansi amasankhidwa ngati malo ofotokozera, komwe mphamvu yamagetsi ya conductor kapena mphamvu yamagetsi pansi imayikidwa pa zero. Chifukwa chake ngati mfundo ili ndi mphamvu yamagetsi ya 12 Volts, kusiyana kwa mphamvu yamagetsi pakati pa mfundo imeneyo ndi nthaka ndi 12 Volts. Pa batire ya 6 Volt, kusiyana kwa mphamvu yamagetsi pakati pa terminal yabwino ndi terminal yoyipa ndi 6 Volts. Chifukwa gawo la kusiyana kwa mphamvu yamagetsi ndi Volt, kusiyana kwa mphamvu yamagetsi pakati pa mfundo ziwiri nthawi zambiri kumatchedwa voltage.
Equation ya kusiyana kwa mphamvu zamagetsi yomwe ili pamwambapa ikhoza kulembedwanso motere:
Ngati chaji q idutsa mu kusiyana kwa mphamvu yamagetsi V ab , mphamvu yamagetsi imasintha ndi ΔEP. Mwachitsanzo, chaji ya Coulombs 2 imadutsa mu kusiyana kwa mphamvu yamagetsi ya 12 Volts, mphamvu yamagetsi imasintha ndi (2 C)(12 V) = 24 Joules. Momwemonso, ngati chaji ya Coulomb 4 imadutsa mu kusiyana kwa mphamvu yamagetsi ya 24 Volts, mphamvu yamagetsi imasintha ndi (4 C) (24 V) = 96 Joules.
Choncho, kusintha kwa mphamvu yamagetsi (ΔEP) kumagwirizana ndi chaji (q) ndi voltage (V ab ). Chaji yamagetsi ndi voltage zikakwera, kusintha kwa mphamvu yamagetsi kumawonjezeka. Mphamvu yamagetsi imagwirizana ndi kuthekera kogwira ntchito, kotero ngati kusintha kwa mphamvu yamagetsi kuli kwakukulu, ndiye kuti kuthekera kogwira ntchito nakonso n'kofunika.
Equation ya kusiyana kwa V pamwambapa ikadali yodziwika bwino. Kuti mupeze equation ya V yowonjezereka, onaninso kusiyana kwa mphamvu yamagetsi m'munda wamagetsi wofanana komanso kusiyana kwa mphamvu yamagetsi komwe kumachitika chifukwa cha chaji imodzi.
Mphamvu yamagetsi m'munda wamagetsi wofanana
Kusiyana kwa V pakati pa mfundo ziwiri mu gawo lamagetsi lofanana, mwachitsanzo, mfundo a ndi mfundo b, kungawerengedwe pogwiritsa ntchito equation ili pansipa:
V ab = kusiyana kwa V pakati pa mfundo ziwiri, E = malo amagetsi, ndi d = mtunda pakati pa mfundo ziwiri.
V yopangidwa ndi single charge
V pa mfundo chifukwa cha chaji imodzi yomwe imapanga mphamvu yamagetsi ikhoza kuwerengedwa pogwiritsa ntchito equation:
V ab = kusiyana kwa V pakati pa mfundo ziwiri, k = Coulomb constant, Q = single charge yomwe imapanga magetsi, r = mtunda pakati pa charge Q ndi point yomwe V imawerengedwa.
Ubale pakati pa mphamvu yamagetsi (E) ndi mphamvu yamagetsi (V)
Munda wamagetsi E ndi kuchuluka kwa vekitala, pomwe V ndi kuchuluka kwa sikitala. Kuchuluka kwa vekitala kumakhudza njira kotero kuti zimakhala zovuta kuwerengera poyerekeza ndi kuwerengera kuchuluka kwa sikitala. Kuti zikhale zosavuta kuwerengera munda wamagetsi, pogwiritsa ntchito equation yomwe imafotokoza ubale pakati pa munda wamagetsi ndi V.
Chiyerekezo cha kusiyana komwe kwafotokozedwa kale chalembedwanso motere:
Mwa masamu, ntchito ndi zotsatira za mphamvu ndi kusamuka, komwe mphamvu ndi zotsatira za mphamvu ndi mphamvu zamagetsi. Ubale pakati pa ntchito, mphamvu, ndi kusamuka ukufotokozedwa kudzera mu equation ili pansipa:
Ngati ma equation awiri omwe ali pamwambapa aphatikizidwa pamodzi, ndiye kuti equation yatsopano imapangidwa motere:
E = malo amagetsi, V ab = kusiyana kwa mphamvu yamagetsi pakati pa mfundo ziwiri monga mfundo a ndi b, d = mtunda pakati pa mfundo ziwiri.
Chigawo cha kusiyana kwa mphamvu ndi Volt, ndipo chigawo cha mtunda ndi mita kuti mphamvu yamagetsi iwonetsedwe mu mayunitsi a Volts pa mita (V/m).
Equation iyi ingagwiritsidwe ntchito kudziwa gawo lamagetsi (lofanana) lodziwika kuti kusiyana kwapakati pa mfundo ziwiri ndi mtunda pakati pa mfundo ziwiri. Kutengera ndi equation, gawo lamagetsi ndi lofanana ndi V ndipo limafanana ndi mtunda. Izi zikutanthauza kuti V ikakwera, gawo lamagetsi limakhala lalikulu komanso mtunda umakhala wokwera, gawo lamagetsi limakhala laling'ono.
