269609 A uniform circular disc of radius \(R\) lies in the XY plane with its centre coinciding with the origin of the coordinate system. Its moment of inertia about an axis, lying in the XY plane, parallel to the \(X\)-axis and passing through a point on the \(Y\)-axis at a distance \(y=2 R\) is \(I_{1}\). Its moment of inertiaabout an axis lying in a plane perpendicular to \(X Y\) plane passing through a point on the \(x\)-axis at a distance \(x\) \(=d\) is \(I_{2}\). If \(I_{1}=I_{2}\) the value ofd is