A.算術(shù)和B.2倍C.相量和D.1/q
A.脈振磁場(chǎng)B.圓形旋轉(zhuǎn)磁場(chǎng)C.橢圓形旋轉(zhuǎn)磁場(chǎng)D.不確定
A.4/5τB.5/6τC.6/7τD.不確定