作者akw102000 (大白)
看板Physics
标题[题目] 普物电学
时间Thu Apr 26 04:19:28 2007
[领域]电位与电位能
[来源] 课本习题
[题目]
http://0rz.tw/3f2Bb
A Geiger counter is used to detect charged particles emitted by
radioactive nuvclei. It consists of a thin, positively charged
central wire of radius Ra surrounded by a concentric conducting
cylinder of radius Rb with an equal negative charge. The charge per
unit length on the inner wire is λ(unit C/m). The cylindrical
assembly is filled with lowpressure inert gas. Charged particles
ionize some of these gas atoms; the resultinig free electrons are
attracted toward the central wire. If the radial electric field is
strong enough, the freed electrons gain enough energy to ionize other
atoms, causing an "avalanche" of electrons strike the central wire,
generating an electric"signal." Find the expression for the electric
field between the wire and cylinder, and show that the potential
difference between Ra and Rb is Va-Vb=ΔV=(λ/2πε)ln(Ra/Rb)
[瓶颈] 其实题目我看不太懂orz。好像是说中间那条wire和外面的cylinder中间
会有一个够强的电场解离周围的气体分子。那跟他要我证明的式子有什麽
关系呀?而且我不会求柱状跟管状的电场or电位...
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◆ From: 140.113.187.150
1F:→ mathfeel:高斯面求电场再求电势差 04/26 06:27
2F:→ akw102000:可是外面的cylinder 跟中间的wire 电量加起来不是0吗? 04/26 18:00
3F:→ mathfeel:cylinder以外是,以内不是 04/28 04:41