1873年，比利时工匠格拉姆参加维也纳世博会，一次偶然的机会，他发明了电动机，关于电能转化为机械能的众多技术马上被产品化

B D A C C

小说；法；都德；小弗郎士的所见所闻所感；小弗郎士；韩麦尔先生

Since 1873 Maxwell (Maxwell) built since the basic equations of electromagnetic field theory, electromagnetic waves obtained a rapid development. At present, the research into the electromagnetic fields, already used widely, such as the antenna radio waves propagation, optical fiber communication and mobile communications, radar technology, microwave and electromagnetic imaging, etc. Electromagnetic wave propagation in the actual environment is very complex, such as all kinds of complicated target scattering, complex structure in the radiation, the antenna waveguide and microstrip structure of transmission, etc. With the rapid development of the computer technology, a large amount of numerical calculation method of the electromagnetic fields are constantly emerging, and get widely. Electromagnetic field of mathematical model is solving actual analysis, due to Maxwell equations, Maxwell equations is a set of differential equation or integral equation, electromagnetic field main numerical analysis method based on spatial discretization into the differential equation method and based on the surface or internal scattering body discretization integral equation method two kinds big. FDTD method was) belong to the differential equation method, finite difference time domain method is simple, intuitive and mesh dissection results of simple, etc. In recent years the FDTD is developing very rapidly, and in many ways are important application, including antenna design, microwave circuit design, emc analysis, electromagnetic scattering calculation, photonics, application, etc.
This paper firstly gives an overview of the electromagnetic field calculation method, then analyzed the basic principle algorithm FDTD algorithm are given, the basic principle of one-dimensional, in turn 2d and 3d electromagnetic wave propagation simulation by matlab language programming steps and problems should be paid attention to, and analyzed their simulation results with matlab language, finally come to the electromagnetic wave propagation FDTD algorithm based on simulated programming, some conclusions.

解题思路：通电导线在磁场中受到安培力，A、C是由于受到安培力而发生转动，根据左手定则可确定安培力的方向，即可确定转动方向．

根据题意可知，A是可动磁铁，B是固定导线，导线中电流方向向上，根据安培定则判断可知磁场中逆时针（从上向下看），N极受到的磁场力沿逆时针，则A沿逆时针方向转动．
C中电流方向向下，根据左手定则判断可知，C受到的安培力沿顺时针方向，故C沿顺时针方向转动．故AC正确，BD错误．
故选：AC

点评：
本题考点： 安培力．

考点点评： 此题根据左手定则来确定安培力的方向，同时根据相对运动来确定各自转动方向．