The number of tangents that can be drawn from an external point to a circle is

In the given figure, $\mathrm{RQ}$ is a tangent to the circle with centre $\mathrm{O}$. If $\mathrm{SQ}=6 \mathrm{cm}$ and $\mathrm{QR}=4 \mathrm{cm}$ then $\mathrm{OR}$ is equal to

In a circle of radius $7 \mathrm{cm}$, tangent $PT$ is drawn from a point $P$ such that $PT=24 \mathrm{cm}.$ If $O$ is the centre of the circle, then length $OP=$?

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In the given figure, $PT$ is a tangent to the circle with centre $O.$ If $OT=6 \mathrm{cm}$ and $OP=10 \mathrm{cm}$, then the length of tangent $PT$ is

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In the given figure, point $P$ is $26 \mathrm{cm}$ away from the centre of a circle and the length $PT$ of the tangent drawn from $P$ to the circle is $24 \mathrm{cm}$. Then, the radius of the circle is

In the given figure, $AB$ and $AC$ are tangents to the circle with a centre $O$ such that $\angle BAC=40°$, then $\angle BOC$ is equal to