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Question
Find out the amount of the work done to separate the charges at infinite distance.
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Solution
The amount work done to separate the charges at infinity will be equal to potential energy.
Potential energy of the system U = `U_(q.2q) + U_(q-4q) + U_(2q-4q)`
`U = (kq(2q))/l + (kq(-4q))/l + (k2q(-4q))/l = (-10kq^2)/l`
Thus work done to seperate them to infinity W = U = `(-10kq^2)/l`
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