第1讲电场,AB,q,【答案】BC,【答案】B,【答案】ACD,【答案】D,【答案】D,【答案】C,【答案】BD,【答案】AB,【答案】BC,【答案】D,【答案】BD,【答案】C,【答案】AC,【答案】AC,【答案】BD,【答案】CD,第2讲磁场,BILsin ,左手定则,Bqvsin,左手定则,洛伦兹力作为向心力,【答案】B,【答案】D,【答案】A,【答案】C,【答案】C,【答案】0.5 N0.2 m,【答案】AC,【答案】AC,【答案】C,【答案】D,【答案】见解析6.5104 s,【答案】C,【答案】A,【答案】D,【答案】AD,【答案】C,【答案】C,【答案】B,【答案】A,【答案】C,【答案】AD,【答案】AD,【答案】ACD,【答案】垂直纸面向里i2,