Circle And System Of Circles Question 247

Question: Consider the circles $ x^{2}+{{(y-1)}^{2}}= $ $ 9,{{(x-1)}^{2}}+y^{2}=25 $ . They are such that

[EAMCET 1994]

Options:

A) These circles touch each other

B) One of these circles lies entirely inside the other

C) Each of these circles lies outside the other

D) They intersect in two points

Show Answer

Answer:

Correct Answer: B

Solution:

Centres and radii of the given circles are Centres: $ C_1(0,\ 1),\ C_2(1,\ 0) $ ; Radii : $ r_1=3,\ r_2=5 $ .

Clearly, $ C_1C_2=\sqrt{2}<(r_2-r_1) $ . Therefore one circle lies entirely inside the other.