Question

if the chord of the larger circle of radius B units touches the smaller circle of radius a units then its length is
root a square minus b square
root b square minus A square
2root a square minus b square
2 root b square minus A square ​

Answer 1

Length of the chord is 2√a square - b square

Answer 2

Answer:

length of chord $AB=2\sqrt{a^{2}-b^{2} }$

Explanation:

. Chord of larger circle will be the tangent to smaller circle.

So OC is perpendicular to chord AB and bisects it.

By Pythagoras theorem, in right angled triangle ACO,  

OA2 =OC2+CA2

$a^{2} =b^{2} +CA^{2}$

$\sqrt{a^{2} -b^{2} } = CA$

AB=2CA [perpendicular drawn from Centre bisect the chord]

$AB=2\sqrt{a^{2}-b^{2} }$