题目内容
一台小型发电机产生的电动势随时间变化的规律图像如图甲所示,已知发电机线圈内阻为20.0Ω,现外接一只“100V,125W”的灯泡,如图乙所示,则:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357511280.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241343575733603.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241343576055457.png)
A.此时刻线圈中感应电流为0
B.通过灯的电流随时间t的变化规律是sin100πt(A)
C.灯泡能正常发光
D.灯泡的实际功率是80w
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357511280.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241343575733603.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241343576055457.png)
A.此时刻线圈中感应电流为0
B.通过灯的电流随时间t的变化规律是sin100πt(A)
C.灯泡能正常发光
D.灯泡的实际功率是80w
D
穿过线圈的磁通量发生变化,有感应电流产生,A错;感应电动势峰值为100![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357651336.png)
V,电流峰值为![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357698727.png)
A,由图示位置开始转动,产生的时正弦图像,通过灯的电流随时间t的变化规律是
sin100πt(A),B错;电流有效值为1A,灯泡正常发光的电流为P/U="1.25A" ,所以灯泡不能正常发光,C错;灯泡的实际功率为
,D对;
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357651336.png)
V,电流峰值为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357698727.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357651336.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357651336.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134357948753.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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