Relative Positions of Two Circles

IMPORTANT

Relative Positions of Two Circles: Overview

This topic covers concepts such as, Concentric Circles, Intersecting Circles and Distance Between Centres etc.

Important Questions on Relative Positions of Two Circles

HARD
IMPORTANT

The radius of the circle, having centre at (2, 1), whose one of the chord is a diameter of the circle x 2 + y 2 - 2 x - 6 y + 6 = 0

HARD
IMPORTANT

Check whether the given two circles touch each other, do not touch each other or intersect each other by making a quadratic equation

x2+6x+y2+5y+10=0

x2+4x+y2+3y+12=0

HARD
IMPORTANT

Check whether the given two circles touch each other, do not touch each other or intersect each other by making a quadratic equation

x2+5x+y2-4y-9=0

x2+4x+y2-3y-7=0

HARD
IMPORTANT

Check whether the given two circles touch each other, do not touch each other or intersect each other by making a quadratic equation

x2+4x+y2+3y+8=0

x2+3x+y2+4y+10=0 

MEDIUM
IMPORTANT

Check whether the given two circles touch each other, do not touch each other or intersect each other by making a quadratic equation

x2-4x+4+y2-6y+9=9

x2-2x+1+y2+2y+1=16

HARD
IMPORTANT

If the circles x2+y2=9 and x2+y2+2αx+2y+1=0 touch each other internally, then α is equal to

MEDIUM
IMPORTANT

Find the equation of the circle passing through (1, 1) and the points of intersection of the circles x2+y2+13x-3y=0 and 2x2+2y2+4x-7y-25=0.

MEDIUM
IMPORTANT

Find the equation of the circle passing through the points of intersection of the circles x2+y2-x+7y-3=0 and x2+y2-5x-y+1=0 and with its centre on the line y+x=0.

MEDIUM
IMPORTANT

Prove that the two circles x2+y2-4=0 and 2x2+2y2-11=0 are concentric.

HARD
IMPORTANT

If S, S1, S2 be the circles of radii 5,3,2 respectively. If S1 and S2 touch externally and they touch internally with S. The radius of circle S3 which touches externally with S1 and S2 and internally with S is

HARD
IMPORTANT

If two circles pass through A(1,0) and B(2,-1) and the y -axis is a common tangent, then find the sum of possible radii.

HARD
IMPORTANT

If the circles x2+y2+(3+sinβ)x+(2cosα)y=0 and x2+y2+(2cosα)x+2cy=0 touch each other, then the maximum value of c is lesser than or equal to

MEDIUM
IMPORTANT

The two circles x2+y2=ax and x2+y2=c2 c>0 touch each other, if ca is equal to

HARD
IMPORTANT

The circle x2+y2=1 is completely contained in the circle x2+y2+4x+3y+k=0, if

MEDIUM
IMPORTANT

Two circles with centre at O and O' and radii 5cm and 2cm respectively as shown in the figure. If AB and CD are two common tangents to both the circles. Then AB2-CD2 is equal to :

Question Image

HARD
IMPORTANT

The number of common tangents to the circles
x2+y2-2x-4y+1=0 and x2+y2-12x-16y+91=0, is

MEDIUM
IMPORTANT

The circles x2+y2-10x+16=0 and x2+y2=r2 intersect each other at two distinct points, if

HARD
IMPORTANT

If the circles x2+y2=9 and x2+y2+2αx+2y+1=0 touch each other internally, then α is equal to

HARD
IMPORTANT

Tangents drawn from the point P(1, 8) to the circle x2+y2-6x-4y-11=0 touch the circle at the points AandB. The equation of the circumcircle of the triangle PAB is

HARD
IMPORTANT

The two circles x2+y2-2x+6y+6=0 and x2+y2-5x+6y+15=0 touch each other