Questions in circle

Select	Question
	The locus of the centre of circle which cuts the circles ${{x}^{2}}+{{y}^{2}}+4x-6y+9=0$ and ${{x}^{2}}+{{y}^{2}}-4x+6y+4=0$ orthogonally is
	Radical axis of the circles $3{{x}^{2}}+3{{y}^{2}}-7x+8y+11=0$ and ${{x}^{2}}+{{y}^{2}}-3x-4y+5=0$ is
	If the chord $y=mx+1$ of the circle ${{x}^{2}}+{{y}^{2}}=1$ subtends an angle of measure ${{45}^{o}}$ at the major segment of the circle then value of m is
	If the two circles $2{{x}^{2}}+2{{y}^{2}}-3x+6y+k=0$ and ${{x}^{2}}+{{y}^{2}}-4x+10y+16=0$ cut orthogonally, then the value of k is
	The centre of the circle, which cuts orthogonally each of the three circles ${{x}^{2}}+{{y}^{2}}+2x+17y+4=0,$ ${{x}^{2}}+{{y}^{2}}+7x+6y+11=0,$ ${{x}^{2}}+{{y}^{2}}-x+22y+3=0$ is
	Equation of radical axis of the circles ${{x}^{2}}+{{y}^{2}}-3x-4y+5=0$ , $2{{x}^{2}}+2{{y}^{2}}-10x$ $-12y+12=0$ is
	If the circle ${{x}^{2}}+{{y}^{2}}+6x-2y+k=0$ bisects the circumference of the circle ${{x}^{2}}+{{y}^{2}}+2x-6y-15=0,$ then $k=$
	If P is a point such that the ratio of the squares of the lengths of the tangents from P to the circles ${{x}^{2}}+{{y}^{2}}+2x-4y-20=0$ and ${{x}^{2}}+{{y}^{2}}-4x+2y-44=0$ is 2 : 3, then the locus of P is a circle with centre
	If two circles ${{(x-1)}^{2}}+{{(y-3)}^{2}}={{r}^{2}}$ and ${{x}^{2}}+{{y}^{2}}-8x+2y+8=0$ intersect in two distinct points, then
	The points of intersection of the circles ${{x}^{2}}+{{y}^{2}}=25$ and ${{x}^{2}}+{{y}^{2}}-8x+7=0$ are