长为 L 的金属棒 ab 以 a 点为轴在垂直于匀强磁场的平面内以角速度 ω 做匀速转动,如图 1-2-6 所示,磁感应强度为 B. (1) 求 ab 棒各点的平均速率; (2) 求 ab 两端的电势差; (3) 经时间 Δ t 金属棒 ab 所扫过的面积中的磁通量为多少?此过程中平均感应电动势为多大?
【简答题】Good manners play an important part in maintaining(保持)peace in society. A man with good manners doesn’t hurt others’ feelings, and therefore he’s on good terms with everyone. In this way he helps to k...
【简答题】Do you know what are good manners (礼貌)?In fact , having good manners is 46 in different countries . In some Asian countries , it is good manners to take off your 47 before you go into a house . 48...