Find out the amount of the work done to separate the charges at infinite distance.

Explanation

Net P.E. of the system
`= (1)/( 4pi in _0) (q^(2) )/( l) [-4+2-8]`
` = ( (-10 )q^(2))/( 4pi in _0 l) `
` therefore ` Work done `( 10 q^(2))/( 4pi in _0l ) = ( 5q^(2)) /( 2pi in _0l ) `