【简答题】
如图所示,一均匀磁场被限制在半径R=20cm的无限长圆柱形空间内,磁场以dB/dt=(4/π)T.s<sup>-1</sup>的恒定速率增加。问图中线框abcda的感生电流是多少?已知线框的电阻<img src="https://nimg.ppkao.com/2018-10/yuanhao/201810111618389346.jpg?sign=3afc653efe1087dcdae3d3ec388dffdf&t=62d1454b" /><br /> <img src="https://nimg.ppkao.com/2018-10/yuanhao/2018101116184335703.jpg?sign=98d9fd0913a7b3019975859d68caa123&t=62d1454b" />