单选题
材料相同、粗细也相同的两个半径不等的导线圆环,小环的半径为r,大环的半径为R,且R=2r.二者置于同一匀强磁场中,且两圆环的平面都与磁场垂直.当磁感应强度随时间做线性增加时,小环中的感应电流为I,则大环中的感应电流为( )
- A、<img src="//wximg.233.com/attached/image/20130108/20130108163678977897.gif" alt="" border="0" />
- B、<img src="//wximg.233.com/attached/image/20130108/20130108163659945994.gif" alt="" border="0" />
- C、<img src="//wximg.233.com/attached/image/20130108/20130108163698249824.gif" alt="" border="0" />
- D、<img src="//wximg.233.com/attached/image/20130108/20130108163680688068.gif" alt="" border="0" />
参考答案 C