如图所示,一个闭合线圈放在匀磁场中,线圈的轴线与磁感线方向成θ=300磁场的磁感应强度随时间均匀变化,线圈导线的电阻率不变,用下述哪个办法可使线圈中感应电流增大一倍?A.把线圈匝数增加一倍B.把线圈面积增加一倍C.把线圈半径增加一倍D.改变线圈轴线与磁感线方向的夹角 答案:C
从下面方框中选择合适的句子,补全对话。
Jane:Who is the girl on the right?
Bill: 1
Jane:Yes, I think so.
Bill:Does she work hard?
Jane:Yes, she does.And 2
Bill: 3
Jane:She is very friendly and polite. 4
Bill:She would like to be a social worker.
Jane: 5