IIT JEE , AIEEE Forum - Physics , Electricity - why electricic potential at a point in infront of an infinitely long line charge is not de

swapnilneal

why electricic potential at a point in infront of an infinitely long line charge is not defined

feynmann

It is defined !!!!!!!!!!

V =

/2 pi

o ln ( x ) + const

neeraj_agarwal_1990

pot. is not defined for an infinite line charge...

potential is the work done to bring charge frm infinity to that point...
its actually the pot. difference b/w inf and that point...

we take the potential at infinity to be 0.....but in case of infinite charges...we can't take potential at infinity to be 0 because the charge is extended to infinity and some field lines will be present wherever u go...

(we assume potential at infinity to be 0 when its 0 in all directions....in this case its not 0 in 2 directions)

so we always get a potential difference b/w two points and not the actual potential...

@feynmann
that x is to be replaced by b/a and its not the potential but pd b/w 2 points at distances a and b from the line charge

elastiboysai

neeraj is right and

electric potential is not defined in case of a line charge and the reason gvn by neeraj is perfect

feynmann

Which way do u go to infinity ?

I mean going to infinity at perpendicular direction to the line charge & not along the line .

In the other case there is something in advanced math called dirac's delta fn . With its help potential can be defined all over the space also ( Of course with an arbitrary const . )

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