A.1/0 B.0/1 C.1/1 D.0/0
A.靜止磁場(chǎng) B.脈動(dòng)磁場(chǎng) C.旋轉(zhuǎn)圓形磁場(chǎng) D.旋轉(zhuǎn)橢圓形磁場(chǎng)
A.s>1 B.s=0 C.0<s<1 D.s<0