Q.

If one of the diameters of the circle x2+y2-10x+4y+13=0 is a chord of another circle C, whose center is (3,2), then the diameter of the circle C is:

1 20  
2 4  
3 12  
4 62  

Ans.

(3)

2x+3y=12,  3x-2y=5,  13x=39⇒x=3, y=2

Centre =C=(5,-2), radius =r=25+4-13=16=4, CM =20,  CP = 6