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Question: Answered & Verified by Expert
Two identical conducting spheres A and B carry an equal charges. They are separated by a distance much larger than their diameters, and the force between them is F. A third identical conducting sphere, C, is uncharged. Sphere C is first touched to A, then to B, and then removed. As a result, the force between A and B would be equal to:
PhysicsElectrostaticsJEE MainJEE Main 2018 (16 Apr Online)
Options:
  • A 3F4
  • B F2
  • C 3F8
  • D  F
Solution:
2515 Upvotes Verified Answer
The correct answer is: 3F8



F=kq2r2 when A and C are touched charge on both will be q2. Then when B and C are touched, qB= q2+q2=3q4
F=kqAqBr2= k ×q2 ×3q4r2=38kq2r2=38F.

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