13. Two identical charges +q and +q are shown below. Rank the magnitude (i.e. strength) of the E-field at locations A, B, and C +9 O EA = EB = EC ( EB > EA = EC O EA = EC > EB O EA > EB> EC 14. A positively charged rod touches an electroscope as shown below. What is the net charge of the electroscope after the rod touches it? Negative O Either positive or zero O Positive Zero Either positive or negative 15. A student wants to conduct an experiment using two point-like source charges and an E-field sensor to test the hypothesis that "the E-field at a point directly between two point-like source charges with the same sign charge will always be zero." Which of the following experiments would be capable of disproving this hypothesis? +4n Sensor +1nC O +4nC Sensor +1nc +1nC Sensor +1nC +1nC Sensor +1nc is since it is true. 16. Which of these statements are true? O If two objects attract, they must be oppositely charged O If two objects attract, at least one of them is charged O If two objects repel they must both be negatively charged Two objects will not attract if one of them is neutral 17. A system consisting of two charged objects, each with charge +Q are brought closer to each other. As they are brought closer to each other, the work done on the system is positive and greater when the objects are still far apart O negative and greater when the objects are still far apart O positive and greater when the objects are closer O negative and greater when the objects are closer 18. Which of the following graphs correctly shows the relationship between the energy in a (proton, proton] system and the distance between the protons? O 19 R Which of the following statements is true about the equivalent resistance R., of this combination? Reg