Two long wires with the same cross section are arranged in air PARALLEL to each other . Assume both have opposite charge densities +λ and -λ. The distance between the axis of the wire is η times larger than the radius(r) of wires cross section . What would be the capacitance of the wires per unit lenth?
Electric field of any point between these wires at a distance x from the +λ charged wire is
The Attempt at a Solution
The problem I am facing is about the limits to be used while integrating Electric field to get the potential .
We know that V=-∫Edx
(Between some limits)
So ∫Edx =λ/2πε[ln(x/ηr-x)]
And if I integrate it over 0 to ηr
The I will get stuff like ln 0 and ln∞ which are obviously not defined . Some other limits just dont get the right answer which is πε/ ln η . [/B]