作者Qmmm (割掉Q)
看板TransPhys
标题[电磁] 台大转 类似题
时间Sat Apr 11 22:20:28 2009
[台大转]
A slab of copper thickness b is placed into a parallel plate
capacitors as shown in figure below; it is exactly halfway
between the plates.
(a)What is the capacitance after the slab is introduced?
(b)If a charge Q is maintained on the plates,
find the ratio of the stored energy before to that after
the slab in inserted.
(c)What is the force on the slab due to the plates?
↙ ______________________
w ╱ plate ╱ ____
╱ ╱￣￣￣￣￣￣↗∕|
↗ ╱←__ L _ → ╱ copper w ∕ |
↑ | ￣￣╱￣￣￣∕￣￣￣￣ ↙ _∕ ∕
a | ╱ |￣￣￣￣￣￣￣￣￣￣￣￣ |b∕
| ╱← x →| _ |∕
↓ | ╱ ￣￣￣￣￣╱￣￣￣￣￣￣￣
￣￣￣￣￣￣￣￣￣￣￣￣
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◆ From: 58.115.138.169
※ 编辑: Qmmm 来自: 58.115.137.72 (04/12 14:19)
1F：→ astrotails:台大真是 = =这给大二的学生还不见得会写吧 04/13 02:14
2F：推 Tashuko:我补习班讲义上有这题耶~"~ 04/13 13:18
3F：→ Qmmm:刚找一下 老吴讲义也有@@ 04/13 14:06
4F：→ Qmmm:to 1F (a)、(b)其实还好 (c)就真的比较难 04/13 22:36
5F：推 astrotails:不好意思看错题了，光看图还以为是cheng後面的习题XD 04/14 14:03
6F：推 SDUM:(c) F=-▽V 原文书有哦(⊙o⊙) 04/15 01:34
7F：→ astrotails:F=-▽V @@? 请问V是指? 04/15 01:39
8F：推 SDUM:打错，是U 位能 04/15 01:55
9F：→ Qmmm:XD 3q 04/15 11:32
10F：→ astrotails:忽然想到一个问题，向量微积分大一会教吗，不好意思 04/15 15:19
11F：→ astrotails:离大一年代太久远了~"~ 04/15 15:19
12F：→ astrotails:像grad divergence crul之类的 04/15 15:20
13F：→ fong1014:梯度至少在教多变数时会教,EX方向导数.算子的内外积 04/15 16:45
14F：→ fong1014:可能要看科系,商管的可能比较不会教 04/15 16:46
15F：→ astrotails:现在小大一真辛苦，印象中我到修电磁才开始学 04/15 19:43
16F：推 IAMROGER:这题不是基本题吗? 04/18 01:08