Question

Two long wires each oflength I are placed on a smooth horizontal table. Wires have equal but opposite charges. Magnitude oflinear charge density on each wire is `lambda`. Calculate the work required to increase the separation between the wires from a to 2a:
A. `(lambda^(2))/(2piepsi_(0)) ln2`
B. `(lambda)/(2piepsi_(0)) ln2`
C. ` (lambda)/(2piepsi_(0)) `
D. ` (lambda^(2))/(2piepsi_(0)a)`

Answer 1

Correct Answer - A

`F=lambdaE`
`w=underset(a)overset(2a)int(lambdaE)dr=overset(2a)underset(a)int(lambda^(2)dr)/(2piepsi_(0)r)`