List of top Mathematics Questions on Circles

The locus of the centre of a circle of radius 2 which rolls on the outside of the circle \( x^{2}+y^{2}+3x-6y-9=0 \) along its circumference is
If the centre of a circle \(S\) is \((2,4)\) and the length of the chord made by the secant \[ x+y+2=0 \] on \(S\) is \(6\) units, then the equation of the circle \(S\) is
If the points \[ (2,0),\ (0,1),\ (4,0),\ (0,k) \] are concyclic, then \(k=\)
The equation of the line that is a tangent to the circle \[ x^2+y^2-6x+4y+12=0 \] is
The equation of the circle passing through the points of intersection of the circles \[ x^2+y^2-2x-4y+1=0, \] \[ x^2+y^2-4x-2y+4=0 \] and having its centre on the line \[ x-2y-3=0 \] is
PQ is tangent to a circle with centre O. If \(\angle POR = 65^\circ\), then m\(\angle PTR\) is
Two concentric circles are of radii 5 cm and 4 cm. Find the length of the chord of the larger circle which touches the smaller circle.
The point of intersection of the lines \[ 2x+3y-12=0 \] and \[ 3x-2y-5=0 \] is the centre of a circle \(S=0\). If \(AB\) is a chord of \(S=0\) and it is a diameter of the circle \[ x^2+y^2-10x+4y+13=0, \] then the radius of the circle \(S=0\) is
If \[ x^2+y^2-2x+2fy+c=0 \] intersects the two circles \[ x^2+y^2+2x-4y+1=0 \] and \[ x^2+y^2-4x-2y-11=0 \] orthogonally, then \[ f+c= \]
The external centre of similitude of the two circles \[ x^2+y^2-4x+6y+4=0 \] and \[ x^2+y^2-2x+2y-2=0 \] is
The centre of a circle \(S=0\) is at \((2,5)\) and its radius is \(r\). \(S_1=0\) is a circle which lies in the second quadrant and touches the coordinate axes and intersects the circle \(S=0\) at two points. If the radius of circle \(S_1=0\) is \(2\), then the possible values of \(r\) lie in the interval
Two concentric circles are of radii $5\text{ cm}$ and $4\text{ cm}$. Find the length of the chord of the larger circle which touches the smaller circle.
In two concentric circles with centre O, the radius of outer circle is 25 cm. Chord PQ of the outer circle is tangent to the inner circle at R. If PQ = 14 cm, then the radius of the inner circle is :
Equation of the circle with origin as centre and passing through the vertices of an equilateral triangle whose median is of length \(3\) is:
If the radical axis of the circles \(x^2+y^2+2gx+2fy+c=0\) and \(2x^2+2y^2+3x+8y+2c=0\) touches the circle \(x^2+y^2+2x+2y+1=0\), then:
The tangent to the circle \(C_1:x^2+y^2-2x-1=0\) at the point \((2,1)\) cuts off a chord of length \(4\) units from a circle \(C_2\) whose centre is \((3,-2)\). The radius of circle \(C_2\) is:
If the chord \(y=mx+1\) of the circle \(x^2+y^2=1\) subtends an angle \(45^\circ\) at the major segment of the circle, then the value of \(m\) is:
The radical axis of two orthogonal circles is \(x+1=0\). If one of those circles is \(x^2+y^2=4\), then the equation of the other circle is:
\(T_1,T_2\) are points of contact of a transverse common tangent drawn to circles \[ x^2+y^2+4x-10y+4=0 \] and \[ x^2+y^2-6x+8y+9=0 \] If \(T_1T_2\) is horizontal line, midpoint of segment \(T_1T_2\) is
If circle \[ x^2+y^2+2x+4y+k=0 \] lies totally inside third quadrant and point \[ \left(-\frac12,-\frac12\right) \] lies outside circle, then set of all real values of \(k\) is
Let \(L_{1}\equiv3x+4y-1=0,\; L_{2}\equiv8x-6y+1=0,\; L_{3}\equiv12x+9y-1=0\) be three tangents drawn to the circle \[ x^2+y^2+2gx+2fy+c=0 \] and \(L_1>0,\;L_2>0,\;L_3>0\) at the centre \((-g,-f)\). Then \(g+2f=\)
A circle \(S\) passing through origin cuts another circle \[ x^2+y^2-6x+8y+16=0 \] orthogonally and makes a chord of maximum length on line \[ x-y-2=0 \] then one diameter of circle \(S\) is
The external centre of similitude for circles \[ x^2+y^2+10x-16y-11=0 \] and \[ x^2+y^2-2x+4y-4=0 \] is
If \[ l_1x+m_1y+n_1=0 \] and \[ l_2x+m_2y+n_2=0 \] are tangents drawn from point \((2,-1)\) to circle \[ x^2+y^2=4 \] then \(n_1+n_2=\)
The centre of the circle which intersects the circles \[ x^2+y^2-8x+10y+5=0 \] and \[ x^2+y^2-2x+2y+1=0 \] orthogonally is: