Question

A student has a small metal sphere that hangs from an insulating string. The student, in seeking to determine the charge on the sphere, brings a positively charged rod near the sphere and finds that the sphere is attracted to the rod. The student then brings a negatively charged rod near the sphere, and finds that the sphere is again attracted to the rod. Which of the following conclusions, if any, can be drawn from these results?

a. The sphere must be negatively charged.
b. The sphere must be positively charged.
c. The sphere must be uncharged.
d. No conclusion can be made about the charge of the sphere.

Answer 1

the answer the correct one is c

Step-by-step explanation:

Electric charges of different signs attract and those of the same sign repel. In addition, there are two types of insulating bodies, where the loads are fixed (immobile) and metallic (with mobile loads.

Let's analyze the situation presented

* A rod with positive approaches and the sphere is attracted, so the charge on the sphere is negative

* A rod with a negative charge approaches and the sphere is attracted, therefore the charge of the sphere must be positive.

For this to happen, the sphere must be unloaded and the charge that creates the phenomenon are induced charges because the mobile charges of the same sign as the sphere are repelled.

when checking the answer the correct one is c