An kudin kasa 2.0 mm da gaba 2 mita. Me ke kan harshen?

Don samun yawan takardun kabilu, za a iya amfani da tsarin resistivity:

• R ita ce takarda (yawan: ohms, Ω)

• ρ ita ce resistivity na abincin (yawan: ohms · meters, Ω·m)

• L ita ce gagar ta hanyar kabilu (yawan: m, m)

• A ita ce tashin kabilu (yawan: square meters, m²)

Don kabilun kabilu, resistivity ita ce kusan 1.72×10−8Ω⋅m (babban halitta a 20°C).

Kadan, zan iya samun tashin A na kabilu. Idan kabilu ya fi tashin circular da diameter na 2.0 mm, wannan ya ba r = 1.0 mm, ko 0.001 m. Tsari na tashi na circle ita ce A=πr 2, saboda haka:

Saboda haka, kabilu kabilu da diameter na 2.0 mm da gagar na 2 meters ya fi takarda daga cikin 0.01094 ohms a kan shaida (20°C). Koyaya, babu iya canza cewa takarda na musamman zai iya bambanta wajen kaɗan idan abin da ke kabilu, temperature, da wasu abubuwa.