List of top Quantitative Aptitude Questions on Circles

If the sum of the diameters of two circles is 40 cm and the difference of their radii is 6 cm, then the ratio of the area of the smaller circle to that of the bigger circle is:
Three circles of equal radii touch (but not cross) each other externally. Two other circles, X and Y, are drawn such that both touch (but not cross) each of the three previous circles. If the radius of X is more than that of Y, the ratio of the radii of X and Y is
The area of a circle is numerically equal to its circumference. Find the diameter of the circle.
Let C be the circle \(x^2+y^2+4x-6y-3=0\) and \(L\) be the locus of the point of intersection of a pair of tangents to \(C\) with the angle between the two tangents equal to \(60º\) . Then, the point at which \(L\) touches the line \(x = 6\) is