46. A conducting sphere of radius R carries an excess positive charge and is very far from any other charges. Which one of the following graphs best illustrates the potential (relative to infinity) produced by this sphere as a function of the distance r from the center of the sphere?
(A)
(B)
(C)
(D)
(E)

42. A long wire carries a current of 3.0 A along the axis of a long solenoid (radius = 3.0 cm, n = 900 turns/m, current = 30 mA). What is the magnitude of the magnetic field at a point 2.0 cm from the axis of the solenoid? Neglect any end effects. (A)34 μT (B)64 μT (C)30 μT (D)45 μT (E)4.0 μT

43. A uniform magnetic field is applied perpendicular to the plane of a 60-turn circular coil with a radius of 6.0 cm and a resistance of 0.60 Q. If the magnetic field increases uniformly from 0.20 T to 1.8 T in 0.20 s, what is the magnitude of the emf induced in the coil? (A)7.2 V (B)5.4 V (C)9.2 V (D)12 V (E)16 V

44. A loop of wire (resistance = 2.0 mΩ) is positioned as shown with respect to a long wire which carries a current. If d = 1.0 cm, D = 6.0 cm, and L = 1.5 m, what current(I) is induced in the loop at an instant when the current in the wire is increasing at a rate of 100 A/s? (A)34 mA(B)30 mA(C)27 mA(D)38 mA(E)0.50 mA

45. A conducting rectangular loop of mass M, resistance R, and dimensions a x b is allowed to fall from rest through a uniform magnetic field which is perpendicular to the plane of the loop. The loop accelerates until it reaches a terminal speed (before the upper end enters the magnetic field). If a = 2.0 m, B = 6.0 T, R= 40 2, and M = 0.60 kg, what is the terminal speed? (A) 1.6 m/s (B) 20 m/s (C) 2.2 m/s (D) 26 m/s (E) 5.3 m/s

47. A conducting sphere is charged up such that the potential on its surface is 100 V (relative to infinity). if the sphere's radius were twice as large, but the charge on the sphere were the same, what would be the potential on the surface relative to infinity? (A) 50 V (B) 25 V (C) 100 V (D) 200 V (E) 150 V

48. Point charges q and Q are positioned as shown. If q = +2.0 nC, Q = -2.0 nC, a = 3.0 m, and b = 4.0 m, what is the clectric potential difference, ? (A)8.4 V (B)6.0 V (C)7.2 V (D)4.8 V (E) O V

49. Addition of a metal slab of thickness a between the plates of a parallel plate capacitor of plate separation d is equivalent to introducing a dielectric with dielectric constant x between the plates. The value of x is(A)(d-a)/d(B)d(C)d-a(D)d/(d-a)(E)d/a

50. The magnitude of the magnetic field at point P for a certain clectromagnetic wave is 2.12 µT. What is the magnitude of the electric field for that wave at P ? (c = 3.0 x 108 m/s)(A)636 N/C (B)745 N/C(C) 5.23 µN/C (D) 6.36 µN/C (E)7.45 µN/C

1. 1.25 × 0.25 + 1.222 = ______. (A) 1.5345 (B) 1.535 (C) 1.53 (D) 1.5 (E) 2

2. Over a short interval near time t = 0 the coordinate of a bicycle in meters is given byx(t) = 12t – 4t3 , where t is in seconds. At the end of 1 s, what is the acceleration of the bicycle? (A) 23 m/s2 (B) 15 m/s2 (C) -4 m/s2 (D) -12 m/s2 (E) -24 m/s2