Consider three identical metal spheres, A, B, and C. Sphere A carries a charge o

Question

Consider three identical metal spheres, A, B, and C. Sphere A carries a charge of +3q. Sphere B carries a charge of -q. Sphere C carries no net charge. Spheres A and B are touched together and then separated. Sphere C is then touched to sphere A and separated from it. Lastly, sphere C is touched to sphere B and separated from it. (a) What is the ratio of the final charge on sphere C to q? What is the ratio of the final total charge on the three spheres to q (b) before they are allowed to touch each other and (c)after they have touched?

Explanation / Answer

A = 3q

B = -q

C = 0

after Spheres A and B are touched together and then separated.

charge on each sphere = A' = B' = (3q-q)/2 = q

after sphere C is touched to sphere B and separated from it.

charge on B & C = B"= C' = (q+0)/2 = 0.5q

finally

charge on A = A' = q

charge on B = B" = q/2

charge on C = C' = q/2

part(a)

C/q = q/2q = 1/2   <<<---------answer

part(b)

final charge on spheres before touching = 3q -q+0 = 2q

ratio = 2q/q = 2 <<<---------answer

part(c)

after the spheres are touched total charge = q + q/2 + q/2 = 2q

ratio = 2q/q = 2 <<<---------answer

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects