QUESTION 12 On the x axis, a point charge Q1 = -1.33E-6 C is placed at x = -1.60 m, and another point charge Q2 = +4.77E-6 C is placed at x = +1.80 m. What is the electric field E at the origin, x = 0 m (in N/C; use positive sign if points in the +x direction, and negative sign if E points in the -x direction)? QUESTION 13 A spherical balloon made of rubber (an insulator) has the size of 2.00 m in radius. An amount of charge Q = -9.89E-6 C is uniformly distributed on the balloon. What is the electric field E at the point 2.40 m from the center of the balloon (in N/C; use positive sign if E points away from the center and negative sign if E points toward the center)? QUESTION 14 A spherical balloon made of rubber (an insulator) has the size of 2.00 m in radius. An amount of charge Q = 2.58E-6 C is uniformly distributed on the balloon. What is the electric field E at the point 1.60 m from the center of the balloon (in N/C; use positive sign if E points away from the center and negative sign if E points toward the center)? QUESTION 15 An infinitely large plane carries a uniformly distributed charge such that the charge density is +9.02E-6 C/m. What is the electric field E at the point that is 2.40 m from the plane (in N/C; use positive sign if E points away from the plane and negative sign if E points toward the plane)? QUESTION 16 A Gaussian sphere with radius 1.20 m encloses a point charge Q = +2.25E-6 C at the spherical center. The electric flux through the spherical surface is measured to be 1. Another point charge Q2 = +8.97E-6 C is placed at the point 1.00 m from the spherical center, and another point charge Q3 = 4.47E-6 C is placed at the point 1.50 m from the spherical center. Q remains at the spherical center. The electric flux through the spherical surface is then measured to be 2. What is D2/ 1?