When dealing with charged objects and conductors, it's essential to understand how electric charges interact. Let's break down the scenario involving the two metallic spheres, A and B, and the positively charged glass rod step by step.
Initial Setup
We have two metallic spheres, A and B, placed on insulating stands, which means they cannot lose or gain charge through the ground. When these spheres are in contact, they can share charge freely between them.
Effect of Bringing the Charged Rod Near Sphere A
When a positively charged glass rod is brought near sphere A, it induces a phenomenon known as electrostatic induction. Here’s what happens:
- The positive charge of the rod repels the positive charges in sphere A, causing them to move away from the rod.
- This results in a concentration of negative charges on the side of sphere A closest to the rod and a deficiency of positive charges on the opposite side.
- Since sphere B is in contact with sphere A, the negative charges from sphere A can attract some positive charges from sphere B, leading to a slight positive charge on sphere B.
At this point, sphere A has a net negative charge on the side facing the rod and a net positive charge on the opposite side, while sphere B has a slight positive charge.
Separating the Spheres While the Rod is Near
Next, if we carefully separate spheres A and B while keeping the positively charged rod near sphere A, the following occurs:
- Sphere A retains its induced negative charge on the side facing the rod and a positive charge on the opposite side.
- Sphere B, having been in contact with sphere A, will also retain its slight positive charge.
- When the spheres are separated, sphere A will remain negatively charged, while sphere B will remain positively charged.
This separation effectively "traps" the charges on both spheres, as they are now insulated from each other and cannot redistribute their charges.
Removing the Glass Rod
Finally, when the positively charged glass rod is removed from the vicinity of sphere A, the following happens:
- The induced charges on sphere A will redistribute themselves. The negative charges will move back towards the center of the sphere, neutralizing the positive charge that was induced on the opposite side.
- Sphere A will return to a neutral state, as the charges will balance out.
- Sphere B, however, will remain positively charged because it has lost some of its electrons to sphere A during the induction process and has not been influenced by the rod.
Summary of Charge Distribution
To summarize:
- Initially, both spheres are neutral.
- Bringing the positively charged rod near sphere A induces a negative charge on sphere A and a slight positive charge on sphere B.
- Separating the spheres while the rod is still near maintains the induced charges.
- Removing the rod neutralizes sphere A but leaves sphere B positively charged.
This sequence of events illustrates the principles of electrostatic induction and charge separation, which are fundamental concepts in electrostatics. Understanding these interactions helps in grasping more complex electrical phenomena in physics.
