题目内容
图中电感线圈L的直流电阻为RL,小灯泡的电阻为R,小量程电流表G1、G2的内阻不计,当开关S闭合且稳定后,电流表G1、G2的指针均偏向右侧(电流表的零刻度在表盘的中央),则当开关S断开时,下列说法中正确的是( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241959072122504.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241959072122504.jpg)
A.G1、G2的指针都立即回到零点 |
B.G1缓慢回到零点,G2立即左偏,然后缓慢回到零点 |
C.G1立即回到零点,G2缓慢回到零点 |
D.G2立即回到零点,G1缓慢回到零点 |
B
试题分析:S闭合且稳定时,通过含电流表
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824195907727447.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824195908273304.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824195908273304.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824195908273304.png)
故选B
点评:断开开关的瞬间,L相当于电源,与两个电流计组成闭合回路,电流方向顺时针.
![](http://thumb2018.1010pic.com/images/loading.gif)
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