Te tātaitai ture a Ohm
Whakarautaki mō te whakarerekētanga, te auau, te ātetetanga, te hiko rānei — tāuru i tētahi o ngā rua o ngā whā.
Ka whakahōutia ngā hua i te wā e tātuhi ana.
Mo tēnei tātaitai
Ohm's law is the single most-used relationship in electronics: the voltage across a resistor equals the current through it times its resistance, V = I × R. Rearranged, the current is I = V / R and the resistance is R = V / I. Power — the rate at which the component turns electrical energy into heat or work — adds a second relationship, P = V × I, which combines with Ohm's law to give the two equivalents P = I² × R and P = V² / R. Together these four quantities form the V–I–R–P 'Ohm's law wheel', and knowing any two of them fixes the other two.
This calculator lets you pick which quantity to solve for and enter any two of the others, then returns the full wheel plus the three equivalent power formulas side by side. For example, a 12 V supply driving a 6 Ω resistor gives I = 12 / 6 = 2 A and P = 12 × 2 = 24 W; check it with P = I² × R = 4 × 6 = 24 W and P = V² / R = 144 / 6 = 24 W, all agreeing. Because the tool back-fills every missing value, entering power and current instead is just as valid — 24 W at 2 A returns 12 V and 6 Ω.
Ohm's law holds exactly for any DC resistive circuit and for the resistive part of an AC circuit, which makes it the everyday tool for sizing current-limiting resistors, choosing LED droppers, working out fuse and wire ratings, reading how much a heater or motor will draw, and predicting the heat a resistor must dissipate. It does not by itself describe capacitors, inductors or non-ohmic parts like diodes, where the voltage–current relationship is no longer a straight line.
Ko nga pātai e pā ana
He aha te ture a Ohm?
E kī ana te ture a Ohm ko te auau o te auau puta noa i tētahi kaiārahi e ōrite ana ki te voltage i runga i a ia: V = I × R. Ka whakahōu anō, I = V / R me R = V / I.
He pēhea te kimi i te hiko hiko mai i te ture a Ohm?
Ko te hiko he voltage wā o te auau, P = V × I. Mā te whakamahi i te ture a Ohm ka taea hoki e koe te tuhituhi hei P = I² × R, P = V² / R rānei — e toru katoa e hoatu ana i ngā watts ōrite.
He uara e rua e tāuru ana au?
Ka kōwhiria te nui e ngaro ana ki roto i "Hoatu mō", kātahi ka tāuru i tētahi o ngā rua o ētahi atu e toru. Hei kimi i te ārai ka taea e koe te whakarato i te voltage me te rerenga, te hiko rānei me te rerenga.
Ka taea e au te whakamahi hiko i te wāhi o te whakarerekētanga, te rerenga rānei hei tāuru?
Hei. Mā te āpure hiko hōhonu e taea ai e koe te whakaoti mai i te hiko me tētahi atu nui — hei tauira, he utu 24 W i te 2 A e hoki ana ki te 12 V me te 6 Ω, mā te whakamahi i te V = P / I me te R = P / I².
He mahi te ture a Ohm mō ngā huringa AC?
E pā ana ki te wāhanga ārai o te arawhiti AC. Mō ngā arawhiti me ngā pūkōrero, ngā pūkōrero rānei e whakakapi ana koe i te ārai ki te ārai, ā, ka whiwhi te hiko i tētahi āhuatanga hiko, engari he ārai noa iho te V = I × R i ia wā.
He aha te wera i te mātau kaitautoko - he nui te hiko e whakawāteatia ai?
Ka huri te kaiārahi i te pūngao hiko ki te wera i P = I2 × R watts. Ko te kaiārahi 6 Ω e mau ana i te 2 A e whakawātea ana i te 4 × 6 = 24 W, nō reira e hiahiatia ana he mana nui ake i runga ake i tērā. Ko te whakaiti i te wattage te take noa iho o ngā kaiārahi whakawhāiti, whakawātea rānei.
Ka whakahaeretia e tēnei ngā wāhanga kāore i te paerangi pēnei i ngā pūrere, i ngā LED rānei?
Kāore. E whakaaro ana te ture a Ohm ki tētahi ārai pūmau, nō reira kāore e tauira ana i ngā kaiataata, LEDs, ngā pūrere rānei e tipu ana i te paerangi me te pūngao. Mō tētahi LED ka whakarārangitia e koe tētahi rārangi ārai mai i te pūngao whakarato i te pūngao LED ki mua.
API — whakamahi tēnei tātaitai mai i te waehere
E kī ana tēnei tātaitai hei wāhi mutunga kore JSON - kāore he kī e hiahiatia ana. Ka tukuna ngā uara āpure i raro nei hei tohutoro pātai, JSON rānei. Anything you omit uses the same default this page is pre-filled with; an unknown parameter is a 400, never a silent zero. Ka pānui te papatono API katoa →
Whakamutunga
GET https://calculator.free/api/v1/ohms-law/curl
curl "https://calculator.free/api/v1/ohms-law/?solve=r&voltage=12¤t=2&resistance=6"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/ohms-law/?" + new URLSearchParams({
"solve": "r",
"voltage": "12",
"current": "2",
"resistance": "6"
}));
const data = await r.json();
console.log(data.results);Ko ngā hua he whakataunga mō te tohutohu ahuwhānui anake, ehara i te tohutohu moni, rongoā, tāke rānei.