18. An optical fiber has an index of refraction, n=1.5, and diameter, d = 10.0 um. It is surrounded by vacuum (n=1.0). When light is sent into the fiber along its axis, find the minimum outside radius, R, permitted for a bend in the fiber if no light is to escape?

(A) 16.7 um,
(B) 20.0 um,
(C) 25.0 um,
(D) 30.0 um,
(E) 50.0 um.

14. A plane electromagnetic (EM) sinusoidal wave propagates in the x direction. Suppose the wavelength is 500.0 nm and the electrical field has an amplitude of 300.0 V/m. What is the intensity (average of poyting vector) of this EM wave (uo = 4π X 10-7N/A2,ε0= 8.85x10-12 F/m) (A)477.5 J/s.m2, (B) 337.6 J/s.m2, (C) 238.7 J/s.m2 , (D) 168.8 J/s.m2, (E) 119.4 J/s.m2.

15. The switch of this circuit is closed at t=0, what is the voltage across capacitor (Vc) after a long time (>> time constant) when the capacitor and inductor are in the steady state? (A) IV, (B) 2V, (C) 3V, (D) 4V, (E) 6V.

16. A particle with charge IC is at the origin (x = 0.0 m). A particle with charge -4C is at x = 2.0 m on the x axis. What finite value(s) of x is the electric potential zero? (A) -2 and -2/3, (B) -2 and 2/3, (C) -2/3 and 2/3, (D) -2/3 and 2/5, (E) 2/3 and 2/5.

17. The electric dipole moment of O-H bond is 5x10-30 C.m. What is the magnitude of electric dipole moment for water molecule? (sin(52.5°) = 0.79, cos(52.5°) = 0.61) (A)3.05 x 10-30 C.m.(B) 3.95 X 10-30 C.m. (C) 6.10 X 10-30 C.m.(D) 7.90 x 10-30 C.m. (E) 9.65 X 10-30 C.m.

19. For a RLC circuit with L = 10 mH, C = 1.0 μF, and R = 200.0 Ω, when vs(t) = 2sin (10000t), what is the amplitude of output voltage vo(t)?(A) 2.0 V, (B) 1.0 V, (C) 0.707 V, (D) 0.5 V, (E) ＜1.0 mV.

20. A student performed Young's double-slit experiment in air using red light. When he immersed the apparatus in water repeated the experiment, what happens to the interference pattern on the screen? (A) No change happens in the interference pattern. (B) The bright and dark fringes stay in the same locations, but the contrast is reduced. (C) It disappears. (D) The bright fringes are farther apart. (E) The bright fringes are closer together.

1. The scientists performed a(n) _______ to determine how effective the drug was at relieving pain. (A) alphabet (B) discount (C) experiment (D) gasoline

2. The shop assistant says if I leave NTD 3,000 as a _______ , she will keep the dress for me. (A) baggage (B) concert (C) deposit (D) harvest

3. Though over six feet tall, he was small by _______ with his mates on the basketball team. (A) advantage (B) comparison (C) geography (D) politician

4. I cannot explain how I know. I just have a(n) _______ that you have been involved in the accident. (A) intuition (B) obedience (C) parachute (D) reference