医学物理历年试题TestPaper05A - A

The Test Paper of Medical Physics for students of grade 2005

under 7-year teaching system (A)

Score

1. If a light quantum, called photon, has a frequency of?, give the expressions for its

mass and momentum. Answer: m?A. Simple questions (Total: 5 questions; 2 marks for each

question)

h?h?p?, cc22. What are the decay types of the radioactive nuclides?

Answer: ?,?, ? and inner transition

3. There are three kinds of strains to describe the shape change of an object under

different stresses (forces). What are they?

Answer: Tensile strain, volume strain and shearing strain

4. What are the standard conditions for a wave function that is a solution of a

Schr?dinger equation?

Answer: single value, finite and continuous

5. What are the coherent conditions for two mechanical waves?

Answer: same frequency, same vibrational direction and same initial phase or constant initial phase change.

B. Right or wrong (Total: 10 questions, 2 marks for each Score

question ;)

1. The curvature radius is positive if the direction from spherical surface to its center

point is the same as the direction of light. ?? right ? wrong

2. Two steel spheres of radii R1 and R2 are put in a deep tank which contains viscous

fluid, the one with bigger radius goes down slower than the other because the fluid is viscous. ? right ?? wrong

3. The hardness of x-rays depends only on the intensity of x-rays photon.

? right

?? wrong

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4. The equations of the two SHMs are given by

s1?10cos??t???cm,

s2?15cos??t???cm

as they are in phase, the amplitude of the superposition vibration is 25 cm.

?? right ? wrong

5. As the molecules of surface-active agents tend to move to the inside of liquid, it can

greatly reduce the surface tension coefficient of the original liquid. ? right ?? wrong

6. The wavelength of the scattered light in Compton Effect experiment becomes shorter

because it lost some energy during the process of the collision with electron. ? right ?? wrong

7. When light travels through a medium with refractive index 1.5, its wavelength will

become shorter and therefore its frequency will become higher in order to maintain the constant speed of light in the medium. ? right ?? wrong

8. The radioactive nuclides will decay. One of the decay types is ? decay that has three

forms. A student writes the three equations to describe the three types of ? decays as

AZAZAZA-X?Z?1Y?????QA?X?Z?1Y?????QAX??-?Z?1Y???Q??decay??decayelectroncaptureGive your correct choice:

? right ?? wrong

9. In a single-slit diffraction experiment, the center of bright fringes has to be satisfied

with the condition of asin??m?. Where a is the width of the slit; m takes any integer numbers, ? is the wavelength used in the experiment. Such a statement is

? right ?? wrong

10. In damped harmonic motion, the system has the following properties due to the

damped force exerting on the system: (1) the mechanical energy of the system decreases; (2) the vibrational amplitude decreases; (3) the period of the system increases and (4) the vibration goes slower.

?? right

Score:

C. Multiple choice problems (3 marks for each question, total

score: 30)

(Please Note: only one choice is correct!

“None of the above” means that when no one of A, B, C and D is

2

? wrong

1.

2.

3. 4.

5.

6.

correct answer for the question, you choose this one)

When the ideal fluid flows steadily in a horizontal pipe, the relations of the cross-section S of the pipe, the velocity v of the fluid and the pressure p of the fluid is that ___E___.

A. Big S corresponds to small v and small p B. Big S corresponds to big v and big p C. Small S corresponds to small v and big p D. Small S corresponds to big v and big p E. None of the above

Which one of the following is an absolute blackbody? Answer: __D____

A. The body that does not radiate visible light.

B. The body that does not radiate any electromagnetic waves. C. The body that does not reflect visible light.

D. The body that does not reflect any electromagnetic waves. E. None of the above

The intensity of x-rays depends only on the __E__ of x-ray photon. A. hardness B. speed C. number D. frequency E. none of the above

If an object is located 12 cm in front of a lens with focal length 10cm, then you can have ___B___.

A. reduced real image

B. magnified (放大的) real image C. magnified virtual image D. reduced virtual image E. none of the above

Laser is very useful in medical science. Give your best choice for the production of laser. Answer __D___.

A. You need to make the absorption, spontaneous emission and stimulated

emission.

B. You need to make the population inversion and the spontaneous emission. C. You need to make the spontaneous emission and stimulated emission. D. You need to make the population inversion and stimulated emission.

Which of the following is NOT true concerning the emission of electron from a metal surface by a suitable beam of light? ___D_____

A. Increasing the intensity of the beam will increase the number of

photoelectron.

B. Only light of wavelength ? such that ? < ?c (threshold wavelength) can

cause the emission of electrons.

C. Increasing the frequency of light will increase the maximum kinetic

energy of the emitted electrons.

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D. Increasing the intensity of the beam will increase the velocity of the

emitted electrons. E. None of the above.

7. A monochromatic light of wavelength 500nm falls on a double slit of separation 2mm.

If a screen is placed at a distance of 3 m from the slits, find the separation between two dark fringes. ___C____

A. 0.375mm B. 0.75cm C. 0.75 mm D. 3.75 cm E. none of the above

500?10?9?x?L??3?7.5?10?4m?0.75mm ?3d2?10?8. A particle with mass m = 4.0 kg is in SHM at the end of a spring with spring constant k = 16.0 N/m. The initial displacement and velocity of the particle is respectively. The amplitude of the vibration is ____A____ (m).

A. 3.0m D. 4.0

Solution:

2v016162???2 A?x0?2?5??3m

44?5m and 4.0 m/s

B.

5m

C. 16.0m

E. none of the above

9. If a beam of monochromatic light travels from optically thinner medium to optically denser medium, ___C___ A. the wavelength and the frequency of light are unchanged B. its wavelength becomes shorter and its frequency becomes higher C. its wavelength becomes shorter but its frequency is unchanged D. its wavelength becomes longer and its frequency becomes lower E. none of the above

10. Particle with rest mass m0 has a relativistic kinetic energy Ek that is three times of its rest energy. What is the correct relation between m and m0? ___C_____

A. m?2m0 C. m?4m0

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B. m?2m0

E.

D. m?6m0 m?3m0