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The radius of a circle is 20 cm. It is ...

The radius of a circle is 20 cm. It is divided into four parts of equal area by drawing three concentric circles inside it. Then, the radius of the largest of three concentric circles drawn is (a) `10sqrt(5)` cm (b) `10sqrt(3)` cm (c) `10\ ` cm (d) `10sqrt(2)` cm

A

`(sqrt(2)-1)a`

B

`(sqrt(2)+1)a`

C

`(2+sqrt(2))a`

D

`(2-sqrt(2))a`

Text Solution

Verified by Experts

The correct Answer is:
B
It is evident from the Fig. 87 that the radius of the largest circle touching all the circles is
`OP_(1)=OC_(1)+C_(1)P_(1)=sqrt(2)a+a=(sqrt(2)+1)a`
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OBJECTIVE RD SHARMA ENGLISH-CIRCLES-Section I - Solved Mcqs
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