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A.54 Answers to Odd-Numbered Problems 59. (2"/d)(2m e / V/e) 1/2 61. 0.588 T $ 24 N - m 69. (a) 0.501 m (b) 45.0° magnetic field to the right feel upward magnetic force, CHAPTER 30 1. 12.5 T 5. into the paper 7. 26.2 &T into the paper 1 out of the page (b) 6I 1 into the page 11. (a) along the line (y % $ 0.420 m, z % 0) (b) ($ 34.7ˆ j) mN (c) (17.3ˆj) kN/C 13. (a) 4.5 (b) stronger 15. ($13.0ˆ j) &T 17. ($27.0ˆ i) &N 19. (a) 12.0 cm to the left of wire 1 (b) 2.40 A, downward bottom of the page 25. (a) 6.34 mN/m inward (b) greater 27. (a) 0 (b) tangent to the wall in a counterclockwise sense (c) inward 29. (a) (b) 31. 31.8 mA $ 24 A - m 2 (b) down 41. 0.191 T 4 K - A/T - m 47. (a) 8.63 ! 10 45 electrons (b) 4.01 ! 10 20 kg 49. 51. 12 layers, 120 m & 0 I 2"w ln # 1 ( w b $ ˆk &
0 bR
3 3r 2 1 3 & 0 br
2 1 & 0 I 2 (2"R) 2 & 0 I
2"R & 0 I " L
& 0 I 4"x 53. 143 pT away along the axis 2 up 61. (a) 274 &T (b) ($ 274ˆ j) &T (c) (1.15ˆi) mN (d) (0.384ˆ i) m/s 2 (e) acceleration is constant (f) (0.999ˆ i) m/s 63. 81.7 A 65. to the right 69. out of the plane of the paper 71. 73. (a) to the left (b) toward the top of the page CHAPTER 31 1. 500 mV 0 IL/2") ln(1 ( w/h) (b) $ 4.80 &V; current is counterclockwise 11. 283 &A upward $ 1.6t , tending to produce counterclockwise current 15. 272 m 2 B 2 w 2 v/R to the left (b) 0 (c) F % N 2 B 2 w 2 v/R to the left 31. 145 &A 1 35. (a) 7.54 kV (b) The plane of the coil is parallel to B. 37. (28.6 mV) sin(4"t) (c) (3.02 A) sin(377t) (d) (9.10 W) sin 2 (377t) (e) (24.1 mN - m) sin 2 (377t) 43. (b) Larger R makes current smaller, so the loop must travel faster to maintain equality of magnetic force 45. ($ 2.87ˆ j ( 5.75kˆ) Gm/s 2 & 0 I(2r
2 ( a
2 ) " r(4r
2 ( a
2 ) & 0 I(2r
2 $ a
2 ) " r (4r
2 $ a
2 ) 1 3 #& 0 0 R
2 & 0 I 4" (1 $ e $ 2" ) & 0 I 1 I 2 L " R |