The Hindenburg disaster

Presentation on theme: "The Hindenburg disaster"— Presentation transcript:

1 The Hindenburg disaster
6 電流、電阻與電路 The Hindenburg disaster

2 Outline 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 電路

3 6-1 電流 電荷守恆 克希荷夫電流(節點)定理

4 電流密度 J: A/m2

5 電流密度與漂移速度

6 銅的漂移速度 dAl=2.5mm, dcu=1.8mm i=17mA, ρ=9×103kg/m3,M=64×10-3kg/m3

7 6-2 電阻與電阻率 Resistance Resistivity Conductivity

8 電阻率 a 銅為主的合金,包含了12%的錳和4%的鎳 ammeter shunts the legal standard for the ohm b [磷] doped to c [鋁] as an electrical conductor in cryogenic systems

9 電阻的計算 Bad Boys Ravish Only Young Girls But Violet Gives Willingly

10 溫度效應 293K-1.69x10-8

11 The effect of temperature

12 電阻的微觀意義

13 6-3 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

14 I-V curves conductor pn junction diode

15 6-4 Semiconductors 半導體

16 Superconductors 超導體 1911

17 More Maglev - magnetic levitation

18 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. On December 2, 2003, a three-car train set (JR-Maglev MLX01) attained a maximum speed of 581 km/h (361 mph) in a manned vehicle run. 2. Fermilab: 6.5 kM 1 TeV

19 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. horse-power motor

20 BCS Theory - The Cooper pairs
the Nobel Prize in 1972 BCS theory predicted a theoretical maximum to Tc of around 30-40K

21 Negative Temperature Coefficient of Resistivity

22 6-5 電路 6-5.1 直流電路 6-5.2 串聯電阻 6-5.3 並聯電阻 6-5.4 交流電路 6-5.5 虛擬電路實驗

23 6-5.1直流電路 Direct Current Circuit A bimetallic strip flasher

24 Ex.8 簡單直流電路內之電位（電壓）升降 克希荷夫 Kirchhoff 迴路定理

25 Ex.9 The Ammeter and the Voltmeter

26 Ex.10 RC電路 電阻－電容電路

27 Ex.10 (cont) Charging a Capacitor

28 Ex.10 (cont)

29 Ex.10 (cont)

30 Ex.10 (cont) 如果 R = 10M C = 1F 經過46s後，e= 0.01，充電達99﹪ 可用作間歇式雨刷等電路控制。

31 6-5.2 Resistance in series

32 6-5.3 Resistors in parallel

33 Multiloop Circuits The Junction rule: 流入接點之電流必等於流出者
(Kirchhoff’s junction/current rule)

34 解System of equations (聯立方程組)

35 Ex.11 What are the currents?

36 解聯立方程組 pivot equation

37 高斯消去法 Forward Elimination and Back substitution pivot equation
upper triangle Forward Elimination and Back substitution

38 Ex.12 The electric eel Electroplaque 0.15V 0.25Ω電斑

39 The Equivalent circuit

40 The current 0.15V 0.25V Rw=800Ω

41 6-5.4交流電路 Alternating Current Circuit V( t ) = V0Sin2f t
f 頻率 = 60H（赫） V0 尖峰值， 一般家庭約170V

42 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

43 Ex.13 72W 音箱

44 Ex.14 A practical example Quebec Montreal

45 6-5.5虛擬電路實驗