Let A and B be two distinct points on the parabola `y^2=4x`. If the axis of the parabola touches a circle of radius r having AB as its diameter, then the slope of the line joining A and B can be

Let A(x_(1), y_(1))" and "B(x_(2), y_(2)) be two points on the parabola y^(2)=4ax . If the circle with chord AB as a diameter touches the parabola, then |y_(1)-y_(2)|=

Let PQ be a focal chord of the parabola y^(2)=4x . If the centre of a circle having PQ as its diameter lies on the line sqrt5y+4=0 , then length of the chord PQ , is

Let P and Q be distinct points on the parabola y^(2)=4x such that circle,for which PQ is the diameter passes through vertex of the parabola.If area of /_OPQ(O is origin) is 20 and the diameter of circum circle of /_OPQ is d,then (d^(2))/(65) is equal to

Let PQ be the focal chord of the parabola y^(2)=4x . If the centre of the circle having PQ as its diameter lies on the line y=(4)/(sqrt5) , then the radius (in units) is equal to