Question

Two neutral conducting spheres are next to each other and touching each other, They are also each separated from the table with an insulating stand. Then, a negatively charged rod is brought near, but not touching, sphere A. The two spheres are then separated by touching only their insulating base. Finally, the charged rod is removed. What are the charges of sphere A and sphere B?

• A. Sphere A is positive while sphere B is negative.
• B. Sphere A is negative while sphere B is positive.
• C. Both spheres are positively charged.
• D. Both spheres are negatively charged.

Answer 1

Answer: (A)

Sphere A is positive while sphere B is negative.

In figure 1, the electrons in the spheres repel from those on the rod and collect towards right. Hence a positive charge accumulates on the left sphere.

Then the two spheres and the rod are separated. Finally, the left sphere attains positive charge and right sphere attains negative charge.