问题
选择题
如图所示,矩形线圈有N匝,长为a,宽为b,每匝线圈电阻为R,从磁感应强度为B的匀强磁场中以速度v匀速拉出来,那么,产生的感应电动势和流经线圈中的感应电流的大小应为( ) A.E=Bav, B.E=NBav, C.E=Bav, D.E=NBav, ![]() |
答案
答案:D
如图所示,矩形线圈有N匝,长为a,宽为b,每匝线圈电阻为R,从磁感应强度为B的匀强磁场中以速度v匀速拉出来,那么,产生的感应电动势和流经线圈中的感应电流的大小应为( ) A.E=Bav, B.E=NBav, C.E=Bav, D.E=NBav, ![]() |
答案:D
假如你是李华,你的笔友Jim最近沉溺于玩电脑游戏,为此你很担心。请根据下表提示给Jim 写一封信,谈谈你的看法及建议。 要求:1. 词数80左右。2. 要点完整,层次清楚,语法正确。开头和结尾已给出,不计入总词数。
I really feel worried about you. ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ______________________________________________ Yours Li Hua |