Hello Readers,
An analogy can be drawn between different conservation laws. Observe the similarity in various quantities listed below.
Example:
N identical drops of mercury are charged simultaneously to a potential of 10 V. When combined to form one larger drop, the potential is found to be 40 V. The value of N is
[Options]:
(A) 5
(B) 3
(C) 8
(D) 10
Answer: (C)
Let r be the radius of each drop and R be the radius of the larger drop. The volume of N identical drops is equal to the volume of the larger drop.
Let q and Q be the charges on the small drops and the larger drop respectively.
From the law of conservation of electric charge,
The potential of a small drop is
The potential of the larger drop is
Divide equation (3) by equation (4).
Substitute the known values.
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