Tiān-chû-ha̍k (電磁學) sī bu̍t-lí-ha̍k ê chi̍t ê hun-chi, sī choan-bûn thàm-thó gián-kiù tiān kap chû kau-hō͘ koan-hē ê ha̍k-kho. "Tiān-chû-hiān-siōng" sī tài-tiān ê lia̍p-á thàu-kuè tiān-chû-tiûnn sán-sing ê hō͘-siong-chò-iōng.