Two circle with equal radii are intersecting at the points(0, 1) and(0, −1). The tangent at the point(0, 1) to one of the circle passes through the centre of the other circle. Then the distance between the centres of these circles is 

(a) 
1 
(b) 

(c) 
2 
(d) 
2 
Two circle with equal radii are intersecting at the points(0, 1) and(0, −1). The tangent at the point(0, 1) to one of the circle passes through the centre of the other circle. Then the distance between the centres of these circles is 

(a) 
1 
(b) 

(c) 
2 
(d) 
2 
In
^{2}=r^{2 }
⇒r=
So distance between centers=