Questions in circle

Select	Question
	The circle ${{x}^{2}}+{{y}^{2}}+4x-4y+4=0$ touches
	The equation of the circle which touches both axes and whose centre is $({{x}_{1}},\ {{y}_{1}})$ is
	The equation of the circle whose radius is 5 and which touches the circle ${{x}^{2}}+{{y}^{2}}-2x-4y-20=0$ externally at the point (5, 5), is
	The lines $2x-3y=5$ and $3x-4y=7$ are the diameters of a circle of area 154 square units. The equation of the circle is
	A circle touches the y-axis at the point (0, 4) and cuts the x-axis in a chord of length 6 units. The radius of the circle is
	The number of circle having radius 5 and passing through the points (– 2, 0) and (4, 0) is
	The equation of the circle which touches x-axis and whose centre is (1, 2), is
	The locus of the centre of the circle which cuts off intercepts of length $2a$ and $2b$ from x-axis and y-axis respectively, is
	If the lines $3x-4y+4=0$ and $6x-8y-7=0$ are tangents to a circle, then the radius of the circle is
	If the radius of the circle ${{x}^{2}}+{{y}^{2}}$ $-18x+12y+k=0$ be 11, then $k=$