Question

1.Vp and Vg are the phase velocity and group velocity, respectively, of the de Broglie wave for an electron moving with the velocity V, and C is the velocity of light in free space. Which of the following is incorrect?

(a) Vp> Vg (b) Vp>C (c) Vg<C (d) Vg=V (e) Vp=V

2.An atomic force microscope (AFM) probe is essentially a cantilever with a nanosized tip at the free end. One scan mode of AFM is to drive the probe as its resonant frequency while scanning on the specimen surface. Which of the following is NOT the purpose of AFM scanning at the probe's resonant frequency?

(a) To reduce the effect of surface water layer

(b) To reduce wear on AFM tip

(c) To achieve atomic resolution

(d) To increase scan speed

(e) All of the above.

3.Continued from the previous question, which of the following AFM probe has the highest resonant frequency? (assume same cantilever cross-section A= width x height 120 um^2, and same density for both materials)

(a)300 um long silicon cantilever

(b)150 um long silicon cantilever

(c)300 um long silicon nitride cantilever

(d)150 um long silicon nitride cantilever

(e)350 um long silicon cantilever

4.When an AFM probe driven at its resonant frequency is approaching a sample surface, what will happen to its resonant frequency?

(a) increase (b)Decrease (c)Increase, then decrease (d) Decrease, then increase (e) Stay the same.

5.The mass of an electron is 9.11x10^31kg. Comparing the classical definition of momentum with its relativistic generalization, by how much is the classical expression in error if v=0.01c.?

(a) 0.5 % (b) 0.05 % (c)0.005 %(d)0.1 % (e)0.01 %

6.The mass of an electron is 9.11x10^31 kg. Comparing the classical definition of momentum with its relativistic generalization, by how much is the classical expression in error if v=0.9c?

(a)13.4 % (b) 56.3 % (c)1.34 % (d)5.63 % (e) 50 % .

7.When heating a piece of ceramic at 1000 °C, the color changes from white to red. This phenomenon is due to which of the following effect?

(a)Black body radiation effect

(b)Photoelectric effect

(c)Photodiode effect

(d)Phosphorescence effect

(e)Compton effect

8.Electromagnetic waves with different mechanisms will results in different energy, which of the following mechanism will most likely to produce or absorb EM waves with the energy of 10^-3 ev

(a)Rotational Energy Levels

(b)Vibration Energy Levels

(c)compton effect

(d)Atomic spectra

(e)Pair Production

9.Two loudspeakers emit 343 Hz sound waves with an amplitude of 0.10 mm. Speaker 2 is 1.00 m behind speaker 1, and the phase difference between the speakers is 90° What is the amplitude of the sound wave at a point 2.00 m in front of speaker 1?

(a)0.00 mm (b)10 mm (c)0.12 mm (d)0.16 mm

(e)0.20 mm

10.A Michelson interferometer uses a laser with wavelength of 500 nm in vacuum. As a 5.00-cm-thick cell is slowly filled with a gas, 40 bright-dark-bright frings shifts are seen and counted. What is the index of refraction of the gas at this wavelength?

(a) 1.0005 (b)1.0004 (c)1.0003(d)1.0002(e)1.0001

Answer 1