[例题14.2]试求导体中位移电流与传导电流的比值 [解]假定我们在横截面积为S的导体中通以简谐交流电io= lo cos@ t,且电流沿横截面均匀分布,则根据欧姆定律的微分形式j=σE,可得

[例题14.1]一平行板电容器的两极板都是半径为5.0cm的圆导体片设充电 后电荷在极板上均匀分布,两极板间电场强度的时间变化率为 dEdt=2.0× 10Vms.试求:(1)两极板间的位移电流ld;(2)两极板间磁感应强度的 分布和极板边缘处的磁感应强度

一、十九世纪四十年代 二、电磁学的一些在特殊条件下的基本定律已 经相继发现 三、早期的电磁理论 四、Thomson、 Helmholtz的类比研究 五、数学理论已趋成熟 六、建立电磁场理论的时机成熟

北京大学：《电磁学》课程教学资源（习题讲义）6.3 表

The zeroth law of thermodynamics: The expression of the fundamental experiment fact. The first law of thermodynamics: The a statement of conservation of energy for pure thermodynamic system. The second law of thermodynamics: Why we need the second law of thermodynamics?

Chapter 13 temperature, heat transfer, and first law of thermodynamics Thermodynamics study the thermal energy (often 10\ -Universe just after beginning called the internal energy) of systems

The dynamics of many-particle systems is called statistical mechanics. The kinetic theory is a special aspect of the statistical mechanics of large number of particles. Suitable averages of the physical characteristics and motions of individual particles provide information about the macroscopic behavior of the system as a whole

第一章绪论 1、计算下列情况的de- Broglie波长,指出那种情况要用量子力学处理: (1)能量为0.025eV的慢中子n1.67.10240-24克):被铀吸收;

1、氢原子处在基态 求: (1)r的平均值;

1、证明:x=1 2、求在自旋态x()中,Sx和的测不准关系(2()=?