【简答题】直流电动机的调速方式有哪几种?最常用的是什么调速方式?
【多选题】下列选项中,构成外购无形资产入账价值的有( )
【判断题】为减少钢筋松驰的预应力损失,对曲线预应力筋和抽芯成孔长度大于24m的直线预应力筋采用两端张拉。
【单选题】A rectangular coil, with corners labeled ABCD, of length L and width w is placed in a magnetic field B as shown in Figure . If there is a current I flowing through this coil, what is the direction of ...
A.
perpendicular to and into the page
B.
perpendicular to and out of the page
C.
in the direction of the magnetic field
D.
in the opposite direction of the magnetic field
【多选题】下列选项中,构成外购无形资产入账价值的是( )