Circle Questions with Solutions
In coordinate geometry, a circle is the set of points at a fixed distance (the radius) from a fixed point (the centre). This topic covers the standard equation (x - h)^2 + (y - k)^2 = r^2, the general equation x^2 + y^2 + 2gx + 2fy + c = 0 with centre (-g, -f), the diameter form, and parametric equations. Exam questions also test the position of a point relative to a circle, the condition for a line to be a tangent, equations of tangents and normals, the length of a tangent from an external point, and the intersection of two circles. The fastest approach is often to compare the distance from the centre to a line with the radius: equal means tangent, smaller means the line cuts the circle. Practise the circle questions below, each with a step-by-step solution.
- Q1.
Segments of the lines and are diameters of a circle of area 153.94 square units. Then the equation of this circle with integer radius is:
A. B. C. D.easyAsked in NIMCET 2026View solution āŗ - Q2.
The equation represents
A. a pair of coincident linesB. a pair of concurrent straight linesC. a parabolaD. a point circleeasyAsked in AMU MCA 2016View solution āŗ - Q3.
The radius of the circle passing through the foci of the ellipse and having its centre at (0, 3) is
A. 4 unitsB. 3 unitsC. unitsD. unitseasyAsked in NIMCET 2015View solution āŗ - Q4.
The point of intersection of the circle and the line is
A. B. C. D.easyAsked in NIMCET 2018View solution āŗ - Q5.
The equation of the circle passing through the point (4, 6) and whose diameters are along and is
A. B. C. D.easyAsked in NIMCET 2019View solution āŗ - Q6.
For the two circles and , there is/are
A. One pair of common tangentsB. Two pairs of common tangentsC. Three pairs of common tangentsD. No common tangentseasyAsked in NIMCET 2019View solution āŗ - Q7.
A circle with its center in the first quadrant touches both the coordinate axes and the line . Then the area of the circle is
A. B. C. D.easyAsked in NIMCET 2025View solution āŗ