Question

A non-conducting wire is bent into a semi-circle of radius `R` and a charge `+Q` is uniformly distributed over it as shown in the figure. Find the ratio `((V_(A))/(E_(A)))` of the potential `(V_(A))` to the magnitude of the electric field `(E_(A))`, both evaluated at the other end `A` of diameter `AB` that bisects the wire (as shown in the figure)

Answer 1

`E=int(1)/(4piepsilon_(0))(dq)/(r^(2))cosphi`, `V=int(1)/(4piepsilon_(0))(dq)/(r )`, where `r=2R cosphi`