5. The ground state of a harmonic oscillator is , where  The corresponding uncertainty of the momentum observable is
(A)
(B)
(C)
(D)

1. A train of proper length Lo is moving at a velocity v = 0.8c towards a tunnel of which the proper distance is also L0．At time t = O, the front end of the train meets the entrance of the tunnel viewed both from the ground and the train. Suppose the time when the rear end of the train mects the entrance of the tunnei viewed from the ground and the train is tA and t'A, respectively, and the time when the front end of the train meets the exit of the tunnel viewed from the ground and the train is tB and t'B. Which of the following is incorrect? (A) In the frame of the ground, tA ＜ tB. (B) In the frame of the train, t'B ＜ t'A. (C) In the frame of the train, the duration from the train entering the tunnel and entirely get out of the tunnel is. (D) (E)t'A = t'B.

2. A Rydberg atom is one whose excited state is of very large principal number n. When n is large, the energy level spacing is proportional to (A)n(B) logn (C) 1/n(D) 1/n2(E) 1/n3.

3. A positroniumn is an exotic atom consisting of an electron and its anti-particle, a positron, bound together. Its ground state energy is (A) -3.2 eV(B) -6.8 eV(C) -9.4 eV (D) -11.4eV(E) -13.6 ev.

4.A particle of rest mass 1 MeV has a momentum 7.1 x 10-22 kg m/s. The kinetic energy is (A) 0.25 MeV (B) 0.33 MeV (C) 0.50 MeV (D) 0.67 MeV (E) 1.2 MeV.

6. Following 5. Determinc the wave function of the first excited state of a harmonic oscillator: (A)(B)(C)(D) (E) .

7. A radioisotope X has a half life time of 10 years. A sample has an initial decay rate of 1.38 x 10:3 decay/year. How many nuclei decay in 10 years? (In 2 = 0.69) (A) 1011 (B) 1012 (C) 1013 (D) 1014 (E) 1015.  

8. Which of the following is incorrect: (A) The blackbody radiation displays a continuous spectrum. (B) The distribution of energy of the emitters obeys the equipartition of energy in each degree of freedom in blackbody radiation. (C) The radiated wavelength of maximal intensity is inversely proportional to the temperature. (D) The energy of the oscillator is quantized. It can have only certain discrete amounts of energy En = nhf, where n is a positive integer and f is the frequency of oscillation. (E) The correspondence principle states that quantum results must blend smoothly with classical results when the quantum number becomes large.

9. In photoelectric effect experiments, two different materials are illuminated by light of frequency f. The induced electrons passing a pair of parallel plates form a current that can be measured. The pair of plates are applied a voltage to decrease the current. The extinction voltage V is the minimal value of voltage such that the measured current becomes 0. Which of the following plots mostly represents the f-V relation?(A)(B)(C)(D)(E)

10. In the Davisson-Germen experiment, a beam of 60 eV electrons is directed at a crystal, and diffracted electrons are found at an angle θ = 74° relative to the original beam. What is the spacing of the atomic planes of the crystal? (A) 0.1 nm (B) 0.5 nm (C) I nm (D) 2 nm (E) 5 nm.

11. How many wave functions are possible in the n = 5 shell? (A) 9 (B) 16 (C) 20 (D) 25 (E) 30.