Magnetic moment orbital angular momentum 32 7 Eq

Magnetic moment & orbital angular momentum (§ 32 -7) Eq. 40 -3 Eq. 40 -10 Why 負號？ Fig. 40 -4 Einstein-de Haas Exp 氫原子的量子數(Table 40 -1) • 主量子數 principal quantum number n • 軌道量子數 orbital quantum number l • 軌道磁量子數 orbital magnetic quantum number ml • 自旋量子數 spin quantum number s • 自旋磁量子數 spin magnetic quantum number ms

磁矩(magnetic dipole) and 磁域(magnetic domain) (§ 32 -8~ § 32 -11) 磁性材料三種類型： • 反磁性(diamagnetism) • 順磁性(paramagnetism) • 鐵磁性(ferromagnetism) 外加磁場B

陰極射線管CRT（cathode ray tube） crossed fields Fig 28 -7 J. J. Thomson有看到電子嗎？他如何證明電子的存在？ 選速器 Two claims (p 741) & e/m Home Work：Ch 28. Problem 7, 64

discovery of the electron (p 741) Two claims(聲稱、主張): Thomson claimed that these particles are found in all matter. He also claimed that they are lighter than the lightest known atom (hydrogen) by a factor of more than 1000. (The exact ratio proved later to be 1836. 15. ) His m/|q| measurement, coupled with the boldness of his two claims, is considered to be the “discovery of the electron. ”

Sample problem 28 -4 Magnetic bottle Helical Paths 螺旋軌跡 pitch 螺距

紐約時報 April 8, 2008

§ 26 -3 Current Density J (電流密度) 電流 i 是單位時間通過的電荷， 電流密度 J 是單位面積通過的電流 Drift Speed 漂移速度 vd 證明 (26 -7) • Sample Problem 26 -3 • vd = ? • 最後一段：If the electrons drift so slowly, why do the room lights turn on so quickly when I throw the switch? Random motion

§ 26 -6 Random-motion speed (veff，effective speed) 第二段：copper的 veff 約為？ 是 drift Speed 漂移速度 vd 的多少倍？ Random motion