[試題] 102下 黃暉理 普通物理學甲下 第一次小考

[xavier13540 (柊 四千)]

課程名稱︰普通物理學甲下
課程性質︰數學系大一必帶
課程教師︰黃暉理
開課學院：理學院
開課系所︰數學系
考試日期（年月日）︰2014/03/11
考試時限（分鐘）：60
是否需發放獎勵金：是
（如未明確表示，則不予發放）

試題 :

1. ~ 3. 圖片：http://i.imgur.com/cOlm6Hb.jpg

1. A plastic rod with charge density λ, is a circular section of radius r and

   central angle 2π/3. Point O is the center of the curvature of the rod. A

   dipole with charge Q and -Q with distance d is located at O (d<<r). And the

   angle between the dipole moment and the plane of the curvarue is θ.(25 pt.)

                                  →
   (a) What is the electric field E due to the rod at point O? (15 pt.)

                          →                         →
   (b) What is the torque τ on the dipole caused by E ? (5 pt.)

                                                       →
   (c) What is the potential energy U of the dipole in E ? (5 pt.)

2. Figure shows a section of a conducting rod of radius R  = R and length L
                                                         1

   inside a thin-walled coaxial conducting cylindrical shell of radius R  = 10R
                                                                        2

   and the (same) length L. The net charge on the rod is Q  = Q; that on the
                                                          1

   shell is Q  = -2Q. What are the (a) magnitude E and (b) direction (radially
             2

   inward or outward) of the electric field at radial distance r = 2R ? What
                                                                     2

   are (c) magnitude E and (d) the direction at r = 5R ? What is the charge on
                                                      1

   the (e) interior and (f) exterior surface of the shell? (Show your answer by

   Q and R) (10 pt. for (a)(b) and (c)(d), 5 pt. for others)

3. (a) Figure (a) shows a nonconducting rod of length L and uniform linear

   charge density λ. Assume that the electric potential is defined to be V = 0

   at infinity. What is V at point P at distance d along the rod's

   perpendicular bisector? (15 pt.) (b) Figure (b) shows an identical rod

   except that one half is now negatively charged. With V = 0 at infinity, what

   is V at P? (10 pt.)

4. Figure shows a parallel-plate capacitor of plate area A and plate separation

   d. A potential difference V  is applied between the plates by connecting a
                              0

   battery between them. The battery is then disconnected, and a dielectric

   slab of thickness b and dielectric constant κ is placed between the plates

   as shown.

   (a) What is the capacitance C  before the dielectric slab is inserted?
                                0

   (b) What is the electric field E  in the gaps between the plates and the
                                   0

       dielectric slab?

   (c) What is the electric field E  in the dielectric slab?
                                   1

   (d) What is the potential difference V between the plates after the slab has

       been introduced?

   (e) What is the capaitance with the slab in place between the plates of the

       capacitor?

     ▄▄▄▄▄▄▄
                          ↑
   █████████ ↑  │
   ████κ████ │b │d
   █████████ ↓  │
                          │
     ▄▄▄▄▄▄▄       ↓

--
第01話 似乎在課堂上聽過的樣子          第02話 那真是太令人絕望了
第03話 已經沒什麼好期望了              第04話 被當、21都是存在的
第05話 怎麼可能會all pass              第06話 這考卷絕對有問題啊
第07話 你能面對真正的分數嗎            第08話 我，真是個笨蛋
第09話 這樣成績，教授絕不會讓我過的    第10話 再也不依靠考古題
第11話 最後留下的補考                  第12話 我最愛的學分

--
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→ xavier13540 :為什麼我打了這麼久只有16批幣 Q＿＿＿＿＿＿＿＿＿Q
※ 編輯: xavier13540 (140.112.196.111), 06/24/2014 11:27:11
推 Joseph819   :你是不是格式調太久 一直按enter什麼的 字打完建議
→ Joseph819   :先送出 再用編輯方式調格式 不然系統好像會扣p幣
→ xavier13540 :我只是畫個圖而已呀QAQ
→ xavier13540 :enter的話我其他篇也都按很多啊= =