Two rods, X and Y, are made from different electrically insulating materials. A student rubs rod X, which is initially uncharged, with a cloth, then holds it near to rod Y. The two rods repel each other. Which statement explains why repulsion occurs in this experiment?

Answer:

Only electrons are transferred when an object becomes charged. Hence options C, D, G and H are all
incorrect. The object becomes negatively charged if it gains electrons and positively charged if it loses
electrons. For repulsion to occur, two objects must have like charges, so either rod X gained electrons
from the cloth and rod Y was negatively charged (which is not one of the options) or rod X lost
electrons to the cloth and rod Y was positively charged, option F.
The answer is F