57. A particle with mass m and charge q, moving with a velocity v, enters a region of uniform magnetic field B, as shown in the figure below. The particle strikes the wall at a distance d from the entrance slit. If the particle’s velocity stays the same but its charge-to-mass ratio is doubled, at what distance from the entrance slit will the particle strike the wall?
(A) 2d
(B)
(C) d
(D)
(E)

53. The emf E = 1.2 kV, C = 6.5 μF, R1 = R2 = R3 = 0.73 MΩ. With C completely uncharged, switch S is suddenly closed (at t = 0). At t = 0, what is current i1 in resistor R1? (A) 3.3✖10-3 A (B) 3.3✖10-4 A (C) 1.1✖10-4 A (D) 1.1✖10-3 A (E) 2.2✖10-3 A

54. The following shows a rod of length L = 10.0 cm that is forced to move at constant speed v = 5.00 m/s along horizontal rails. The rod, rails, and connecting strip at the right form a conducting loop. The rod has resistance 0.400 Ω; the rest of the loop has negligible resistance. A current i = 100 A through the long straight wire at distance a = 10.0 mm from the loop sets up a (nonuniform) magnetic field through the loop. Find the emf. (μ0 = 4π10-7 T  m/A, ln 2 = 0.693, ln 10 = 2.303, ln 11 = 2.398) (A) 2.4✖10-4 V (B) 5.8✖10-3 V (C) 4.8✖10-5 V (D) 3.9✖10-4 V (E) 8.8✖10-4 V

55. If the five lenses shown below are made of the same material, which lens has the shortest positive focal length? (A) (B) (C) (D) (E)

56. For quantum model, E = hν = hc / λ, where E is photon energy in unit of eV, h is the Planck’s constant ( ), ν is the frequency (s -1 ), λ is the wavelength in meters (m), then E✖λ (eV m) is: (A)  1.24 ✖10- 3 (B)  1.24✖ 10- 4 (C) 1.24 ✖10-5 (D)  1.24✖ 10- 6 (E)  1.24✖ 10-7

58. The position of a particle moving on x-axis is given by  x = , with x in meters and t in seconds. Which statement in the following is correct? (A) The particle is moving in the positive direction of x with a speed of 1.5m/s at t =1.0 s. (B) The acceleration of the particle at t = 1.0 s is -0.50 m / s 2 . (C) The acceleration of the particle is constant. (D) The particle is moving in the negative direction of x with a speed of 0.50m/s at t =1.0 s. (E) The velocity of the particle is constant.

59. A wire loop of area 1000 cm 2 has a resistance of 10 ohms. A magnetic field B normal to the loop initially has a magnitude of 0.1 T and is reduce to zero at a uniform rate in 10-4 s. Thus, the resulting current is: (A) 10000 A (B) 1000 A (C) 100 A (D) 10 A (E) 1 A

60. A rod of semiconducting material with length L and cross-sectional area A lies along the x-axis between x = 0 and x = L . Its resistivity varies with x according to . The material obeys Ohm’s Law. What is the total resistance of the rod? (A)(B)(C)(D) (E)

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