最主要我覺得係要清concept 例如要知lenz law 個induce既magnetic flux 係為左oppose the change of magnetic field 然後果d induce b field 會製造一個emf
其實如果知左條公式係講咩就好易
https://www.youtube.com/channel/UCFl6Zqcsb2bwvn8qqqxBndA 個人覺得呢個channel講得幾好

還沒翻車啊+1