9-1.11 電容器 電容（Capacitance） 平行板電容器 C = ( F 法拉 ) K: 介電常數，真空 = 1 0: 真空電容率 A: 板面積 d : 兩板距離
Ex.4 1.0 F 電容器 d = 1.0mm
9-1.12 Capacitors in parallel
等效電容
9-1.13 Capacitors in series
等效電容
Ex.5 A RAM Chip C = 55fF（10-12） V = 5.3 volt A charged capacitor means that a “one” has been stored.
Ex.6 電容式鍵盤
Ex.6 (cont) A = 9.50 10-5m2 ; k = 3.50 按鍵後d由5.00m減為0.150mm 按鍵後 C = 0.589PF
電容式麥克風
Ex.7 defibrillator (除纖顫機)
心跳停止病人之急救 盡快求助 盡快給予先進的救命治療 盡快實行心肺復甦術(CPR) 盡快除纖顫
人體各部位的電位差 人體的肌肉及神經細胞利用鈉、鉀等正離子及氯負離子執行生化機能；因此造成之電場延伸至人體表面，形成小量之電位差。 心電圖 -電極置於不同位置（A-B，B-C等）即決定不同形狀的心電圖。 腦波圖 -電極置於頭部特定部位，紀錄電位差隨時間之變化。
心電圖和腦波圖 EKG EEG
視網膜電圖 ERG
9-2 電流與電阻 電流、電流密度與漂移速度 電阻與電阻率 歐姆定律 半導體與超導體
9-2.1 電流
9-2.2 電流密度與漂移速度
銅的漂移速度
9-2.3 電阻與電阻率 Resistance Resistivity Conductivity
電阻率
電阻的計算
溫度效應
電阻的微觀意義
9-2.4 Ohm’s Law 流過一電路元件之電流與該元件之電位差成正比 電阻率與電場的大小及方向無關
I-V curves conductor semiconductor
Semiconductors 半導體
Superconductors 超導體
Maglev、MRI and Tevatron 1. The new test line called the Yamanashi Maglev Test Line opened on April 3, 1997 On April 14, 1999, this five-car train set surpassed the speed record of the three-car train set, attaining a maximum speed of 552 km/h in a manned vehicle run. 2. Fermilab: 6.5 kM 1 TeV 3. In May of 2001 some 150,000 residents of Copenhagen, Denmark, began receiving their electricity through HTS (high-temperature superconducting) material. That cable was only 30 meters long, but proved adequate for testing purposes. In the summer of 2001 Pirelli completed installation of three 400-foot HTS cables for Detroit Edison at the Frisbie Substation capable of delivering 100 million watts of power.
Power line and motor 1. In May of 2001 some 150,000 residents of Copenhagen, Denmark, began receiving their electricity through HTS (high-temperature superconducting) material. That cable was only 30 meters long, but proved adequate for testing purposes. In the summer of 2001 Pirelli completed installation of three 400-foot HTS cables for Detroit Edison at the Frisbie Substation capable of delivering 100 million watts of power. 2. 5000 horse-power motor
BCS Theory - The Cooper pairs
9-3 電路 直流電路 串聯電阻 並聯電阻 交流電路 虛擬電路實驗
9-3.1直流電路 Direct Current Circuit A bimetallic strip flasher
Ex.8 Bimetallic Strip Flasher
Ex.9 簡單直流電路內之電位（電壓）升降 克希荷夫 Kirchhoff 迴路定理
Ex.10 The Ammeter and the Voltmeter
Ex.11 RC電路 電阻－電容電路
Ex.11 (cont) Charging a Capacitor
Ex.11 (cont) 如果 R = 10M C = 1F 經過46s後，e= 0.01，充電達99﹪ 可用作間歇式雨刷等電路控制。
9-3.2 Resistance in series
9-3.3 Resistors in parallel
Multiloop Circuits The Junction rule: 流入接點之電流必等於流出者 (Kirchhoff’s junction/current rule)
解System of equations (聯立方程組)
Ex.12 What are the currents?
解聯立方程組
高斯消去法 Forward Elimination and Back substitution pivot equation upper triangle Forward Elimination and Back substitution
Ex.13 The electric eel
The Equivalent circuit
9-3.4交流電路 Alternating Current Circuit V( t ) = V0Sin2f t f 頻率 = 60H（赫） V0 尖峰值， 一般家庭約170V
功率 P（t）= I0V0Sin2 2 f t，取時間平均值 對交流電而言，歐姆定律變成
Ex.14 72W 音箱
Ex.15 A practical example Quebec Montreal
Automatic Coffee Maker
3-way Light Bulb
Electrical Grounding 0.001A : Mild tangling sensation 0.01-0.02A: Muscle spasms 0.2A: fatal (fibrillation)
9-3.5虛擬電路實驗 文件下載 http://www.puhsein.org.tw/ 黃信健教授的科學教學軟體 1, 2, 3, 4, 5, 6, 7
敬請期待 磁學(Magnetism)