Question

In the diagram the smaller circle is drawn such that it passes through the Centre of the larger and touches the larger circle. What is the radius of the smaller circle if the diameter of the larger circle is D?

• A. D/2
• B. D
• C. D/4
• D. 2D

Answer 1

The correct option is C

D/4

In the diagram, the smaller circle touches the larger circle and also passes through its Centre.

Therefore we can say that the line connecting the point of contact of the two circles and the Centre of

the larger circle will be the diameter of the smaller circle. This line is also the radius of the larger circle.

Hence we can say that, the radius of the smaller circle, say r is= $\frac{R}{2}$ R is the radius of the larger circle

r =$\frac{D}{4}$