课程名称︰普通物理学乙
课程性质︰医学系必修
课程教师︰朱士维
开课学院：医学院
开课系所︰医学系
考试日期（年月日）︰2013/11/6
考试时限（分钟）：180分钟
是否需发放奖励金：是，谢谢
（如未明确表示，则不予发放）
试题：
1. [0] During our entire lifetime, interaction with people are inevitable. It
is vital to show mutual respect in these interactions. One of the key
components in successful interaction/communication is to know others'
names. So, please write down the names of our teaching assistants in this
General Physics course (in Chinese or English, be sure you spell correctly).
2. [5] (Order of magnitude estimation) It is known that collagen is the most
abundant protein in our body, and carbohydrate compounds, such as glucose,
are our major energy source. Let's make estimation on the number of
collagen and glucose molecules, Before we start, you are encouraged to guess
which molecule we have more in our body.〈Fact A〉: In human body, protein
constitutes 20％ weight of the whole body, and collagen contributes to about
30％ of the whole-body protein content. The molecular weight of collagen is
about 10000 Dalton, where 1 Dalton is equivalent to 1.66×10^(-27) kg.
〈Fact B〉：In human body, glucose mainly presents in blood. It constitutes
0.1％ weight of the blood, and the weight of blood is about 1/13 of the
whole body weight. The molecular weight of glucose is 180 Dalton. So based
on your estimation, for collagen and glucose, which one is more in our body
in terms of number？
3. [5] (Error and measurement) Let's name the width of your own index finger to
be WIF and use it as the unit for length measurement. Please determine the
width of this A4 paper in the unit of WIF, with an error range. Specify as
many sources of error as possible in your measurement (at least three error
sources are required).
4. [5] (Bonus) Euclid thought that vision involves rays going from the eyes to
the object seen, in analogues to that touch involves hands going from our
our body to the object being touched. Can you design an experiment to prove
that Euclid was not correct？
5. [10] (a) [5] We have shown a beautiful rainbow coming from a prism
illuminated by the white light. This refraction phenomenon is known for
hundreds of years since Newton's time. It is known that Newton favors
particle explanation of light. Please argue that why this prism experiment
can be used to explain the particle nature of light？ (b) [5] (Bonus) The
strongest experimental proofs of wave nature of light are interference and
diffraction. Water wave, which is one of the most common wave in life, also
exhibit interference and diffraction.Other than these two phenomena, is
there any other wave phenomenon that water and light wave both exhibit, and
can be used to prove wave nature of light？
6. [5] For a prism with anomalous dispersion, what is the color distribution
with white light incident onto it？（画图）
7. [5] One important parameter for an optical fiber is its attenuation loss.
The attenuation loss of a good fiber can be as low as 0.1 dB/km, which
means the light intensity becomes 1/10 after propagating 100 km. Assuming
that the attenuation mainly comes from absorption of fiber, in terms of
Beer-Lambert law, please find out the equivalent absorption constant α.
8. [10] Please explain why the sky is blue and why the sunset is red based on
atmospheric scattering.
9. [5] [HW 15.3] What is the focusing power of the cornea？The front and back
radii of the cornea are 7.8 and 7.3 mm, respectively. The refractive
indices of cornea and aqueous humor are 1.38 and 1.33, respectively.
10. [5] Recently, the traffic lights in the street are modified to be
LED-based. Taking green light as an example, there are multiple green LEDs
tightly packed inside. The size of a green LED is 1×1 cm2, and the
distance between two adjacent LEDs is 10 cm. If your angular resolution is
3×10^(-4) rad, which one is the farthest distance that you can distinguish
two adjacent LEDs in the traffic light？
　　A. 0.1m－1m；B. 1m－10m；C. 10m－100m；D. 100m－1000m.
11. [5] In a class demo with a cross, we have shown that one arm of cross
becomes clearer with reduced eye aperture. However, based on the concept of
diffraction, the spitial resolution is higher with larger aperture. It
seems that these two concepts conflict to each other... In our daily life,
　　if we want to see the environment more clearly, we should expand or narrow
　　down our eye aperture？
12. [5] In a class demo, we distributed table spoon to the students so that you
can see your own pupil. The image of pupil you saw on the spoon is
　　A. magnified virtual image；B. magnified real image；
　　C. reduced virtual image；D. reduced real image.
13. [15] The electron single-slit diffraction experiment has been voted as the
most beautiful experiment ever did. Let's analyze this experiment based on
　　uncertainty principle. (a) [5] What is the momentum of a 1-eV electron？
(b) [5] What is the momentum uncertainty if we confine the electron into a
100-nm slit？ (c) [5] Following (b), how large is the minimal width of
electron beam after propagating 10 meters in vacuum？
14. [5] Which one is NOT necessary for MRI？
　　A. Gradient of magnetic field；
　　B. Single-frequency radio-frequency EM wave as a driving source；
　　C. Wide band detection of radio-frequency Em wave；
　　D. Time-resolved detection to determine relaxtion times；
　　E. EM wave frequency is the resonant frequency of nuclei precession.
15. [10] (a) What is the photon energy of the EM wave at Larmor frequency with
1-tesla magnetic field？（γ＝2.68×10^8 1/T‧sec） (b) For an electron to
　　have the same amount of kinetic energy, what is its wavelength？
16. [5] Which one is NOT the effect of myelin sheath in the equivalent
　　circuit？
　　A. Increase the conductivity across axon memebrane；
　　B. Reduce the capacitance across axon memebrane；
　　C. Reduce the electric signal loss along axon；
　　D. Increase the time delay of eletric signal along axon.
17. [5] RC circuit analysis. With rectangular wave guess which one is the
result of this circuit？（附图请找家产，似上课投影片）
18. [5] Since both telescope and microscope are optical systems with two
convex lens, how can we turn a telescope into a microscope？Explain your
　　answer step by step.
‧Mass of electron：9.11×10^(-31) kg, Planck constant：6.63×10^(-34) J‧s,
　1 eV＝1.6×10^(-19) J