A bar magnet is moving downward, south pole first, toward a loop of wire。 Which of the following best describes the current induced in the wire?

(A) Clockwise, as viewed from above

(B) Counterclockwise, as viewed from above

(C) The current alternates

(D) There is no current induced in the wire

(E) The direction of the current cannot be determined from the information given here

译：1．条形磁铁南极是向下移动,首先,对钢丝的循环。下列哪个最好的描述了当前感应线吗?

(A)顺时针方向,从上空俯瞰

(B)逆时针方向,从上空俯瞰

(C)当前的交替

(D)没有电流感应线

(E)电流的方向不能确定从这里给出的信息文献综述

答案选A。 磁铁移动向下创建一个向下的磁通量。使用右手法则,我们发现当前相关通量下降流顺时针

2。 A bar of length 2 cm slides along metal rails at a speed of 1 cm/s。 The bar and rails are in a magnetic field of 2 T, pointing out of the page。 What is the induced emf in the bar and rails?

(A)   V

(B)   V

(C)   V

(D)   V

(E)   V

译：2。长度为2厘米的金属小棒沿金属轨滑动速度为1厘米/秒。金属小棒和金属轨道的磁场为2T，指向页面。金属小棒和轨道的感应电动势是多少？

美国SAT考试的启示及其物理试题的研究(3):http://www.youerw.com/wuli/lunwen_165424.html