Consider three identical metal spheres, A, B, and C. Sphere A carries a charge o
ID: 1591558 • Letter: C
Question
Consider three identical metal spheres, A, B, and C. Sphere A carries a charge of +5q. 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
Here,
initially
qAi = 5 q
qBi = -q
qCi = 0
when A and B are touched
qA = (5q - q)/2
qA = 2q
qB = 2 q
when C and A are touched
qA = (2q+0)/2
qA = q
qB = q
when C and B are touched
qB = (q + 2q)/2 = 1.5 q
qC = 1.5 q
for the final charges on spheres
qA = q
qB = 1.5 q
qC = 1.5 q
a)
Now ,
ratio of final charge on C to q = 1.5
b)
before tocuhing the spheres
ratio of total charge to q = (5 - 1 + 0)
ratio of total charge to q = 4
c)
after the touching
ratio of total charge to q = 1 + 1.5 + 1.5
ratio of total charge to q = 4