A. (a, a)

B. (0, a)

C. (a, 0)

D. (-a, 0)

The equation of the circle whose centre lies in the first quadrant and which touches the coordinate axes and the line (x/3)+(y/4)=1 is x^{2}+y^{2}-2cx-2cy+c^{2}=0, then c=

The equation to the locus of the midpoints of chords of the circle x2+y2-8x+6y+20=0 which are parallel to 3x + 4y+5 = 0 is

The radical centre of the circle x^{2}+y^{2}=1, x^{2}+y^{2}-2x=1, x^{2}+y^{2}-2y=1 is

The length of the common chord of the circles x^{2}+y^{2}+2hx=0, x^{2}+y^{2}-2ky=0 is

If the pole of a line w.r.to the circle x^{2}+y^{2}=a^{2 }lies on the circle x^{2}+y^{2}=a^{4 }then the line touches the circle