How many electrons must be transferred to a body to produce a charge of 125 nc? a. 1.25 x 107 b. 3.45x 1011 c. 1.60x 10-19 d. 7.81 x1011 e. 1.28x 1012 2. protons a. are about 2000 times more massive than electrons. b. are about 2000 times less massive than electrons. c. have 2000 times the charge of electrons. d. have 1/2000 the charge of electrons. 3. charge a is +50 nc and is 10.0 cm from charge b, which is +100 nc. what is true about the forces on the charges? a. the force on a and the force on b are equal in magnitude but opposite in direction. b. the force on a is larger than the force on b, and they are opposite in direction. c. the force on b is larger than the force on a, and they are opposite in direction. d. the force on a and the force on b are equal in magnitude and direction. 4. charges q1 and q2 exert repulsive forces of 10 n on each other. what is the repulsive force when their separation is decreased so that their final separation is 80% of their initial separation? a. 16 n b. 12 n c. 10 n d. 8.0 n e. 6.4 n 5. [in-class discussion wednesday] two positive charges (+8.0 mc and +2.0 mc) are separated by 300 m. a third charge is placed at distance r from the +8.0 mc charge in such a way that the resultant electric force on the third charge due to the other two charges is zero. the distance ris a. 0.25 km. b. 0.20 km. c.0.15 km. d. 0.13 km. e. 0.10 km.