课程名称︰普通物理学甲下
课程性质︰大一某些系必修
课程教师︰王名儒教授
开课学院：
开课系所︰
考试日期（年月日）︰2016/04/19
考试时限（分钟）：110 mins
试题 :
1.
Describe the charge distribution in a metal under the electrostatic condition. You need to use the Guass law to support your argument.
2.
A charge distribution is contained in a ball with radius R and gives the following electric potential V(r)=V_0 exp(-ar) where r<R; V_0 and a are some positive constants. Find out the potential outside this ball, with r>R.
3.
Assuming that the proton has a diameter of 10e-15 m, what is the energy needed to set up the electric field of a proton(r>0.5e-15 m)?
4.
Copper contains 8.4e+28 free electrons per cubic meter. A copper wire of cross-sectional area 7.4e-7 m^2 carries a current of 1A. What is the electron drift speed?
5.
A schematic diagram is shown below(omitted) to illustrate the circuit of an electric eel. Each electroplaque has a 0.15V emf and a 0.25Ω internal resistance. The surrounding water has an equivalent resistance 800Ω. How much current can the eel produce in the water?
6.
Describe the operation principles of the cyclotron and the synchrotron. It will be better to draw some plots in your description.
7.
What is the magnetic field along the Z axis due to a current loop in the X-Y plane centered at the origin with radius R and current I? Show that for z>>R, its form is like a dipole.
8.
Ifwe suddenly introduce an emf ε to a single-loop circuit containing a resistor R and an inductor L, find out the current in this loop as a functionof time.
9.
One connects the two ends of a resistor(resistance R), an inductor(inductance L), and a capacitor(capacitance C) with an alternating voltage source in parallel. Assuming the voltage source has a functional form V(t)=V_0 cos(ωt), find out the total current I as a function of t and related parameters(e.g. R,L,C).
10.
Write down the Maxwell's equations and use an example to demonstrate the contribution made by Maxwell giving the correct answer.