【简答题】如图所示,匀强磁场的磁感应强度 B = 0.2 T ,磁场宽度 l = 4 m ,一正方形金属框边长为 l ′ = 1 m ,各边的电阻 r = 0.2 Ω ,金属框以 v = 10 m/s 的速度匀速穿过磁场区,其平面始终保持与磁感线方向垂直, cd 边始终与磁场边界平行 . 求: (1) 画出金属框穿过磁场区域的过程中,各阶段的等效电路图; (2) 画出金属框穿过磁场区域的过程中,金属框内感应...
【简答题】The greatest recent changes have been in the lives of women, during the twentieth century there was an unusual shortening of the time of a woman’s life spent in caring for children. A woman marrying a...
【简答题】阅读理解。 Women have been scientific discoveries since ancient times. Twelve women have won the Nobel Prize for science, one of the highest honors in the world. Some women scientists never married,...