If OA and OB be the tangents to the circle $x^2+y^2-6x-8y+21=0$ drawn from the origin O, then AB =

Q. If $OA$ and $OB$ be the tangents to the circle $x^2+y^2-6x-8y+21=0$ drawn from the origin $O$ then $AB=$

Q. If the pair of tangents are drawn from origin O to the circle $x^2+y^2-6x-8y+21=0$, meets the circle at A and B , the lengths of AB is

Q. The common tangent to the circles $x^2+y^2=4$ and $x^2+y^2+6x+8y-24=0$ intersects the coordinate axes at $A$ and $B$ respectively. If $OA$ and $OB$ are equal to half of the length of the major and minor axes of an ellipse respectively, where $O$ is the origin, then the eccentricity of the ellipse is

Q. Suppose two perpendicular tangents can be drawn from the origin to the circle $x^2+y^2-6x-2py+17=0$, for some real $p$. Then $\left|p\right|$ is equal to

Q. Circle $x^2+y^2=5$ and $x^2+y^2-3x+y=0$ intersect at point $A$ & $B$. Lines $OA$ and $OB$ are drawn through origin. Then