12. The dashed circle represents the cross section of a closed spherical Gaussian surface. There are three charges inside the surface: -4.0 mC, -2.0 mC, and an unknowm third charge. The net electric flux passing through the Gaussian surface is +3.39 x 108 N-m²/C. What is the third charge? A. +3.0 mC -2.0 mC -4.0 mC В. -31.6 mO C. -9.0 mC D. -3.0 mC E. +9.0 mC q=? 13. A hollow spherical conductor carries a net charge of Q=-1 µC. The hollow interior of the sphere contains a point charge of q = +3 µC. How much charge resides on the exterior surface of the conductor? Q=-1 µC A. -1 µC B.+2 μ С. -0.5 дС D. +1 μC Ε.-3 μC q = +3 µC 14. Two point charges, each +2.00 µC, are 0.500 m apart. How much work must you do to move a third charge, also +2.00 µC, from infinitely far away to occupy a point that is 0.500 m from each of the first two charges? A. 0.432 J B. 0.144 J C. 0.117 J D. 0.288 J E. 0.216 J +2.0 µC +2.0 μC 0.50 m

12. The dashed circle represents the cross section of a closed spherical Gaussian surface. There are three charges inside the surface: -4.0 mC, -2.0 mC, and an unknowm third charge. The net electric flux passing through the Gaussian surface is +3.39 x 108 N-m²/C. What is the third charge? A. +3.0 mC -2.0 mC -4.0 mC В. -31.6 mO C. -9.0 mC D. -3.0 mC E. +9.0 mC q=? 13. A hollow spherical conductor carries a net charge of Q=-1 µC. The hollow interior of the sphere contains a point charge of q = +3 µC. How much charge resides on the exterior surface of the conductor? Q=-1 µC A. -1 µC B.+2 μ С. -0.5 дС D. +1 μC Ε.-3 μC q = +3 µC 14. Two point charges, each +2.00 µC, are 0.500 m apart. How much work must you do to move a third charge, also +2.00 µC, from infinitely far away to occupy a point that is 0.500 m from each of the first two charges? A. 0.432 J B. 0.144 J C. 0.117 J D. 0.288 J E. 0.216 J +2.0 µC +2.0 μC 0.50 m