Question

Question 1.13: Suppose the spheres A and B in Exercise 1.12 have identical sizes. A third sphere of the same size but uncharged is brought in contact with the first, then brought in contact with the second, and finally removed from both. What is the new force of repulsion between A and B?

Class 12 - Physics - Electric Charges And Fields Electric Charges And Fields Page-47

Answer 1

Hey mate!

Here's your answer!!

When an uncharged sphere is brought in contact with sphere A, half of the charge will be shifted to third sphere. So the charge q1 on sphere A becomes 3.25x10‒7 C.

Again on contact of sphere C with sphere B, redistribution of charge will happen and charge q2 on sphere B gets [{(6.5+3.25) × 10‒7}/2 =] 4.875x10‒7 C.

Then, by the same formula for force, we get

F = [(9x109).(q1.q2)] / r2
F = 5.7x10‒3 N.

$hope \: it \: helps \: you.$