AP EAMCET Medical 23 Sep 2020 Shift 2 Paper

Two concentric coplanar circular loops of radii r1 and r2 carry currents i1 and i2 respectively, inopposite directions ( i1 clockwise and i2 anticlockwise.) The magnetic induction at the centre of the loops is half of that due to i1 alone at the centre. If r2 = 2r1, the value of i2/i1=