作者yihsianghuan (unknown)
看板TransPhys
标题[电磁] 算不同介电常数电容的问题
时间Sun Apr 26 15:56:01 2009
A parallel-plate capacitor with a plate separation d has a capacitance
C1. A slab of dielectric material of dielectric constant K and thickness d is
inserted between the plates.
(A)Calculate the new capacitance C2 with the dielectric slab.
(B)If thickness of the inserted dielectric slab is d/2,calculate the new
capacitance C3 with the dielectric slab.
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 61.224.29.124
1F：推 waanapple:(A) C2=KC1 方法:先假设带电Q由电场高斯定律求出E 05/04 14:21
2F：→ waanapple: 注:还要假设电界质产生感应电荷q~然後.... 05/04 14:24
3F：→ waanapple: 最後得到:C2=[Q/(Q-q)]C1~~其中[Q/(Q-q)]=K 05/04 14:26
4F：→ waanapple:(B) 看成两电容串连(一含电界质K另一个不含~板距都d/2) 05/04 14:29
5F：→ waanapple: 1/C3=1/2KC1+1/2C1 得C3 05/04 14:31
6F：→ waanapple:注解:平行板电容推导:先设Q~由高斯得E~积分得V带入C=Q/V 05/04 14:34