I have been unable to find text references for this material in my book:
The problem gives me two spheres, Sphere A has unevenly distributed negative charges, Sphere B has negative charges distributed almost evenly near the edge of the sphere, forming a circle inside the sphere.
Q: The negative charge distribution over the surface of two isolated spheres is dipicted. One of the spheres is made of copper and the other is made of rubber. Identify the sphere that depicts charge distribution of copper and that of rubber. Support the answer with an explanation.
Copper is a conductor, so voltage will be constant on its surface. To get constant voltage, there must be a constant E field at the surface, which means charge is uniformly distributed.
In insulators, one can have any charge distribution.
To identify the sphere that depicts the charge distribution of copper and rubber, we need to understand the properties of these materials when it comes to charge distribution. Here's how you can analyze the scenario:
1. Look for relevant information in your textbook: While you mentioned that you couldn't find text references for this material in your book, it is always a good idea to start by checking the index or table of contents for any relevant sections or keywords related to charge distributions, conductors, or insulators. Look for any information about the behavior of charges on copper and rubber materials.
2. Understand conductors and insulators: In general, conductors are materials that allow electric charge to flow easily through them, whereas insulators do not. Copper is a good conductor, while rubber is an insulator.
3. Analyze the charge distribution on each sphere: Sphere A has unevenly distributed negative charges, while Sphere B has negative charges distributed almost evenly near the edge, forming a circle inside the sphere.
4. Apply the knowledge of conductors and insulators: Since Sphere A has unevenly distributed charges, it does not align with the behavior of copper, which is known to distribute charge evenly across its surface. However, Sphere B has charges predominantly concentrated near its edge, forming a circle. This arrangement aligns more closely with the behavior of an insulator like rubber, as charges do not flow freely and collect or accumulate near the edges.
5. Present your reasoning: Based on the properties of conductors and insulators, we can conclude that Sphere A depicts charge distribution more characteristic of copper, while Sphere B resembles rubber. You can explain that the even distribution of charges on Sphere A indicates the charges are freely flowing across its surface, pointing to it being a conductor like copper. On the other hand, the concentrated charges near the edge of Sphere B suggest that the charges are not freely flowing, suggesting it is an insulator like rubber.
Although I couldn't find text references for your specific scenario, following these steps should help you make an educated inference based on your understanding of conductors and insulators.