Two identical metal balls with charges +2Q and -Q are separated by som

1.	Two identical metal balls with charges +2Q and -Q are separated by some distance, and exert a force F on each other. They are joined by a conducting wire, which is then removed. The force between them will now be(a) F (b) F/2 (c) F/4 (d) F/8
Answer» Correct Answer is: (d) F/8 F = k 2Q²/d², where d = separation. Since charge is shared, the charge on each ball = 1/2 (2Q - Q) = Q/2. The force now becomes F' = k (q/2)²/d² = 1/4. k Q²/d² = F/8.

Two identical metal balls with charges +2Q and -Q are separated by some distance, and exert a force F on each other. They are joined by a conducting wire, which is then removed. The force between them will now be(a) F (b) F/2 (c) F/4 (d) F/8

Answer»

Correct Answer is: (d) F/8

F = k 2Q²/d², where d = separation.

Since charge is shared, the charge on each ball = 1/2 (2Q - Q) = Q/2.

The force now becomes F' = k (q/2)²/d² = 1/4. k Q²/d² = F/8.

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Two identical metal balls with charges +2Q and -Q are separated by some distance, and exert a force F on each other. They are joined by a conducting wire, which is then removed. The force between them will now be(a) F (b) F/2 (c) F/4 (d) F/8

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