badfox007
幼苗
共回答了19个问题采纳率:89.5% 举报
![](https://img.yulucn.com/upload/9/61/961bcd019584dc66081fe0f481812350_thumb.jpg)
100
起辉电压与交流电压的有效值相等,意即电压瞬时值u≥
![](https://img.yulucn.com/upload/a/cb/acb77340e9176b6444e42969022ecb4f_thumb.jpg)
时,氖管发光;而当电压瞬时值u<
![](https://img.yulucn.com/upload/a/cb/acb77340e9176b6444e42969022ecb4f_thumb.jpg)
时,氖管熄灭,画出u="50sin314t" V的图象,如下图所示,由图象看出在第一个半周期内发光时间Δt=t
2 -t
1 ,再由电压瞬值表达式可得
![](https://img.yulucn.com/upload/a/cb/acb77340e9176b6444e42969022ecb4f_thumb.jpg)
=U
m sin314t,即sin314t=
所以314t
1 =
![](https://img.yulucn.com/upload/3/3e/33e57042ea29e2ddc8bb1153504714e7_thumb.jpg)
,314t
2 =
![](https://img.yulucn.com/upload/1/a6/1a6df4f22d18fb3c0ec6d2dd8cc4b78e_thumb.jpg)
π
t
1 =
![](https://img.yulucn.com/upload/3/84/3840810da14438a9bd3bc3688a1a162c_thumb.jpg)
,t
2 =
可得Δt=t
2 -t
1 =
所以,每次发光持续的时间为
因为1个周期内可发光2次,所以1 s发光次数n=2·
![](https://img.yulucn.com/upload/6/bf/6bfbd427d8bd971a5801a467eec2e073_thumb.jpg)
=2×
![](https://img.yulucn.com/upload/8/99/899d47573f477039d1a97ccf5a10af28_thumb.jpg)
=100.
1年前
9