A.主觸頭先分?jǐn)喔綦x開(kāi)關(guān)后分?jǐn)?br /> B.隔離開(kāi)關(guān)先分?jǐn)嘀饔|頭后分?jǐn)?br /> C.主觸頭、隔離開(kāi)關(guān)同時(shí)分?jǐn)?/p>
A.較大電流電路 B.較小電流 C.短路電流
A.電磨損 B.化學(xué)磨損 C.機(jī)械磨損