A rod made from insulating material carries a net charge, while a copper sphere is neutral. The rod and the sphere do not touch.
(a) Is it possible for the rod and the sphere to attract one another?
(b) Is it possible for the rod and the sphere to repel one another?
Explain both answers
b) no
(a) It is possible for the rod and the sphere to attract each other. This can occur if the net charge on the rod causes an imbalance of charges on the copper sphere, even though it is initially neutral. This happens due to a phenomenon called polarization. When the charged rod is brought close to the sphere, the positive charges in the copper atoms within the sphere are attracted toward the rod, while the negative charges are repelled. As a result, there is a redistribution of charges in the sphere, creating an imbalance and causing an attractive force between the rod and the sphere.
To determine if the rod and the sphere will attract, you can perform a simple experiment. First, bring the charged rod close to the copper sphere without touching them. Observe if there is any motion or attraction between the two. You can also use a small object, like a piece of paper or a light fiber, and place it close to the sphere to see if it is attracted. If there is an attraction between the rod and the sphere, it indicates that the charges are imbalanced, leading to an attractive force.
(b) It is not possible for the rod and the sphere to repel each other. This is because the copper sphere is neutral and has an equal number of positive and negative charges. The charged rod induces polarization in the sphere but does not transfer any charges to it. As a result, there are no like charges present to repel each other.
To confirm that the rod and the sphere do not repel each other, you can perform a similar experiment as in part (a). Bring the charged rod close to the copper sphere without touching them and observe if there is any repulsion or motion away from each other. If there is no repulsion observed, it confirms that the rod and the sphere do not possess like charges and thus do not repel each other.