题目

有一个1000匝的线圈，在0.4s内通过它的磁通量从0.02Wb增加到0.10Wb，则线圈中的感应电动势_________V．如果线圈的电阻是10欧，把一个电阻为990欧的电热器连接在它的两端，通过电热器的电流是__________A. 答案：200   2I can’t remember _____ made the teacher give Mary the permission to leave the class earlier. A. that it was what    B. what it was that    C. what was it that    D. that was it what