A non conducting ring of radius 0.5m carries a total charge of 1.11*(10 pow -10)C distributed non uniformly on its circumference producing an electric field Every where in space. The value of line integral (integration from l=1/0 to l=0)- Edl (l=0 being center of the ring) in volt is
1. +2
2. -1
3. -2
4. 0
(please give complete explanation)