An uncharged metal sphere, A, is on an insulated base. A second sphere, B, of the same shape, size and material carrying a charge + Q is brought close to but not touching with sphere A. (a) Describe what happens to charges on spheres A and B as they are brought close together but not touching. (b) If we now remove sphere B and place it far away, what is the charge on sphere A? (c) How is this charge (if any) distributed?

a) when we approach sphere B with a positive car Q, it attracts negative charges from sphere A

b) phere A with a charge equal to zero

c) The charges are not distributed since there is no physical contact

Explanation:

a) Electric charges are neither created nor destroyed, they are only distributed, when we approach sphere B with a positive car Q, it attracts negative charges from sphere A in such a way that while the two spheres are close, each one has a charge + Q / 2.

b) when sphere B moves away, it no longer attracts negative charges from sphere A, so they move away from each other and neutralize themselves with positive charges, leaving sphere A with a charge equal to zero

c) The charges are not distributed since there is no physical contact between the two spheres, only a charge is induced when they are close, but when moving away each one is left with its initial charge