A.30° B.60° C.120°
A.原方匝數(shù)多,導(dǎo)線截面小 B.副方匝數(shù)多,導(dǎo)線截面小 C.原方匝數(shù)多,導(dǎo)線截面大
A.減小 B.不變 C.增大