(1) Two small spheres attract each other electrostatically. This can occur for a variety of reasons. Which of the following statements must be true?
a. Neither carries an excess charge
b. At least one of the spheres is charged.
c. Both are charged
d. Both have the same charge.
(2) Charges q1 and q0 exert repulsive force of 10 N on each other. What is the repulsive force when their separation is decreased so that the final separation is 50% of their initial separation?
(3) An electron is moving horizontally east in an electric field that points vertically downward. The electric force on the electron is
a. directed upward
b. directed downward
c. directed to the west