Let there is a circle having center O

Let AB is the tangent to the smaller circle and chord to the larger circle.

Let P is the point of contact.

Now, draw a perpendicular OP to AB

Now, since AB is the tangent to the smaller circle,

So, ∠OPA = 90

Now, AB is the chord of the larger circle and OP is perpendicular to AB.

Since the perpendicular drawn from the center of the circle to the chord bisect it.

So, AP = PB

Hence, in two concentric circles, the chord of the larger circle which touches the smaller circle is bisected at the point of contact.