A.增大 B.不變 C.減小
A.匝數(shù)多,導(dǎo)線細(xì) B.匝數(shù)多,導(dǎo)線粗 C.匝數(shù)少,導(dǎo)線細(xì) D.匝數(shù)少,導(dǎo)線粗