Óa
(Tùi Oá choán--lâi)
Oá ia̍h watt sī ēng lâi piáu-sī kong-lu̍t (power) ê tan-ūi, sī 1 chióng SI cho͘-ha̍p tan-ūi, kì chò W. 1 W sī ta̍k bió chò kang 1 joule, khiā kóng:
- 1 W = 1 J/s = 1 N m / s = 1 kg·m2·s−3
Ūn-tōng-oân ē-tàng hoat-hui kaù 900 W. Khì-chhia ê iăn-jín ē-tàng kaù 100,000 W.
Nā chhù lāi ê tiān-hoé-kiû-á, iok-liōng 40 - 100 chek, kap W kāng ì-sù.