The length of the tangent drawn from the point $(2, 3)$ to the circle $2(x^2 + y^2) - 7x + 9y - 11 = 0$ is:

Let $S$ be the circle in the $XY$-plane which touches the $X$-axis at point $A$,the $Y$-axis at point $B$,and the unit circle $x^2+y^2=1$ at point $C$ externally. If $O$ denotes the origin,then the angle $\angle OCA$ equals:

Consider the circle $x^2+y^2-4x-2y+c=0$ whose centre is $A(2,1)$. If the point $P(10,7)$ is such that the line segment $PA$ meets the circle in $Q$ with $PQ=5$,then $c$ is equal to

Let $C$ be a circle with radius $\sqrt{10}$ units and centre at the origin. Let the line $x+y=2$ intersect the circle $C$ at the points $P$ and $Q$. Let $MN$ be a chord of $C$ of length $2$ units and slope $-1$. Then,the distance (in units) between the chord $PQ$ and the chord $MN$ is

The length of the chord intercepted by the circle $x^2+y^2-6x+8y-5=0$ on the line $2x-y=5$ is equal to $L$ units. Find $L$.

The number of common tangents to the circles $x^2 + y^2 - 2x - 1 = 0$ and $x^2 + y^2 - 2y - 7 = 0$ is: