The surface charge density of a thin charged disc of radius R is σ. The value of the electric field at the centre of the disc is sigma/(2in_0)`. With respect to the field the centre, the electric field along the axis at a distance R from the centre of the disc reduces by
Options:
(a) 70.7%
(b) 29.3%
(c) 9.7%
(d) 14.6%