[TOC] # Chapter 5 - Electric Field in Material Space ## current in conductors :::spoiler current in conductors ![](https://i.imgur.com/qgPDCb0.png) ![](https://i.imgur.com/RauH9D3.png) ::: ## current 有兩種 :::spoiler 1. conduction current > ![](https://i.imgur.com/whpR87X.png) > ![](https://i.imgur.com/JUo4Klx.png) > ![](https://i.imgur.com/oOzNYVB.png) ::: :::spoiler 2. convection current 對流電流 > ![](https://i.imgur.com/OGrAIWG.png) ::: ## Conductor ![](https://i.imgur.com/5h6lGBp.png) ### Resistivity of Conductors ![](https://i.imgur.com/Gpw8S4u.png) ![](https://i.imgur.com/GswmGIi.png) ### Joule's Law :::spoiler Power ![](https://i.imgur.com/wLybszC.png) ::: :::spoiler Power Density ![](https://i.imgur.com/qczcRxL.png) ::: ![](https://i.imgur.com/QcvT3BL.png) ## Continuity Equation ![](https://i.imgur.com/ajslSal.png) ## Relaxation Time ![](https://i.imgur.com/W6oip5r.png) # Chapter 6 - Electrostatic Boundary-Value Problems Poisson's and Laplace's Equations 得到電場的三種方法 :::spoiler rho (向量場) ![](https://i.imgur.com/bTJSUzG.png) ::: :::spoiler 高斯 (向量場) ![](https://i.imgur.com/egJtxxg.png) ::: :::spoiler V (純量場) ![](https://i.imgur.com/X0wRdcx.png) ::: 但是有兩種限制 :::spoiler ![](https://i.imgur.com/4GJiJln.png) ::: 所以我們就要進入 Boundary-Value Problems 首先,從 Poisson's equation and Laplacian equation 開始 ## Poisson's equation :::spoiler Poisson's equation ![](https://i.imgur.com/UM6I2tx.png) ::: ## Laplacian equation :::spoiler Laplacian equation (Poisson's equation 的特例) ![](https://i.imgur.com/IC6n1Dz.png) ::: ## Uniqueness theorem :::spoiler Uniqueness theorem ![](https://i.imgur.com/YCwC7hz.png) ![](https://i.imgur.com/dBKC3y7.png) ![](https://i.imgur.com/RU16lBB.png) ![](https://i.imgur.com/pqzxIV2.png) 邊界條件常見型態 ![](https://i.imgur.com/FzmY8iJ.png) ::: ## Solving Poisson's or Laplace's equations :::spoiler ![](https://i.imgur.com/xcut1xc.png) ::: ## Method of separable variables ![](https://i.imgur.com/BSGazYC.png) 然後討論 lamda>=<0 的情況 :::spoiler lamda>0 ![](https://i.imgur.com/Ma2hNNo.png) ::: :::spoiler lamda=0 ![](https://i.imgur.com/EO98DuD.png) ::: ## Solutions for 2D Laplace's equations Cartesian Coordinate System ![](https://i.imgur.com/0C16UmQ.png) beta<0,和beta>0,式子長的一樣 ![](https://i.imgur.com/EUAJ5iO.png) 所以 V 有 2X2 種型態 或是 ![](https://i.imgur.com/72bsNqZ.png) 所以 V 有 2X2 種型態 所以 ![](https://i.imgur.com/dHBNEuZ.png) ![](https://i.imgur.com/IMmITjt.png) 注意:要注意 possible complete solutions 不要寫成 invalid solutions # 心得 這段雖然數學偏重看似困難,但是實質上如果我們把過程看過,然後知道了過程以後忽視它,只記得她的結果的話,那麼就沒有想像中那麼難,主要是寫題目比較難。很開心最近稍微有一點漸入佳境的感覺了,加油 fighting!