9. Which of the following statements about absolute pressure P, gauge pressure P_G and atmospheric pressure P₀is true?
(A) P is the same as P_G at 273 K.
(B) P₀ + P_G is the absolute pressure P.
(C) Gauge pressure P_G is always positive.
(D) Absolute pressure P is the atmospheric pressure P₀ at 15°C.
(E) None of the above.

5. Which of tiie following statements of lenses is true? (A) Nearsighted glasses use concave lenses. (B) Farsighted glasses use concave lenses. (C) Simple magniiying glass uses concave lenses. (D) Ail of the above. (E) None of the above.

6. An object is placed 2f away from a thin and double convex lens of focal length f. Which of the following descriptions on its image is true? (A) erect, real, and magnified (B) inverted, virtual, and reduced (C) inverted, real, and the same size (D) erect, virtual, and magnifled (E) inverted, real, and reduced

7 Order the following electromagnetic waves by wavelengths from the shortest to the longest: (i) visible light, (ii) radio waves, (iii) infrared (iv) ultraviolet light, (v) x-ray. (A) (v)＜(ii)＜ (i)＜(iv)＜(iii) (B) (v)＜(iv)＜(i)＜(iii)＜(ii) (C) (iii)＜(i)＜(iv)＜(ii)＜(v) (D) (v)＜(iv)＜(iii)＜(i)＜(ii) (E) (iii)＜(i)＜(iv)＜(v)＜(ii)

8. According to flie laws of tiiermodynamics, which of the following statements is correct? (A) Thermodynamic perpetual machine is possible. (B) Heat always flows from a colder to a hotter object. (C) The entropy of an isolated system never decreases. (D) All thermodynamic processes are reversible. (E) Work done on a system is always greater than the heat added.

10. Which of the following gases would exhibit a more narrow K^xweH-Boltzmann speed distribution at a given temperature? (A) Hydrogen (H2) (B) Oxygen (O2) (C) Nitrogen (N2) (D) Helium (He) (E) Argon (Ar)

11. Which of the following descriptions of electrons is correct? (A) Electrons are massless. (B) Electrons are positively charged. (C) Electrons can travel at the speed of light. (D) Electrons obey the Pauli exclusion principle. (E) None of the above.

12. Under what condition does the magnetic force on a charged particle perform work? (A) When the particle moves parallel to the magnetic field. (B) When the particle moves perpendicular to the magnetic field. (C) When the particle moves at an angle to the magnetic field. (D) When lhe magnetic field is non-uniform. (E)None of tiie above.

13. According to Lenz's law, when changing the magnetic flux throu^i a coil, the direction of the induced current in a coil is such lhatit... (A) opposes the change in magnetic flux. (B) supports the change in m^netic flux. (C) depends on the resistance of the coil. (D) is unrelated to the magnetic flux. 也)aligns with the magnetic flux.

14. See the right figure, there is a metallic sphere, on 的ich a constant electric potential is applied, A chained particle moves fh＞m point A to point B through three different kinds of paths denoted as I, II, and III. Through which path does the particle gain the most electric eneigy?(A) I (B)II (C) III (D) All the same (E) It depends on the sign of the charge.

15. Refer to the figure. A conducting loop (square coil of wire) is pulled at constant velocity through a uniform magnetic field entering the plane. Which of the following statements is correct?(A) Current is induced in the loop in the clockwise direction. (B) Current is induced in the loop in the counterclockwise  direction. (C) Alternating current is induced in the loop.  (D) Charge separation occurs； negative chafes are accumulated at the bottom edge. (E) Charge separation occurs； negative charges are accumulated at the top edge.