If `x^2+y^2-2x-6y+10-r^2=0` and `x^2+y^2+6x=0` intersect orthogonal to each other ,then the value of r

When the circles x^(2)+y^(2)+4x+by+3=0 and 2(x^(2)+y^(2))+6x+4y+C=0 intersect orthogonally,then find the value of c is

If the circles x ^(2) + y ^(2) + 5x -6y-1=0 and x ^(2) + y^(2) +ax -y +1=0 intersect orthogonally (the tangents at the point of intersection of the circles are at right angles), the value of a is

If the two circles 2x^(2) +2y^(2) -3x+6y+k=0 and x^(2) +y^(2) -4x +10y +16=0 cut orthogonally, then the vlaue of k is-

The circles x^(2)+y^(2)-12x-12y=0 and x^(2)+y^(2)+6x+6y=0:( a) intersect in two points.(b) touch each other externally.(c) touch each other internally.(d) None of these

For the circles x^2 + y^2 - 2x + 3y + k = 0 and x^2 + y^2 + 8x - 6y - 7 = 0 to cut each other orthogonally the value of k must be

The circles x^2+y^2-12 x-12 y=0 and x^2+y^2+6x+6y=0. touch each other externally touch each other internally intersect at two points none of these

The circles x^2+y^2-12 x-12 y=0 and x^2+y^2+6x+6y=0. a.touch each other externally b.touch each other internally c.intersect at two points d.none of these

The circles x^2+y^2-12 x-12 y=0 and x^2+y^2+6x+6y=0. a.touch each other externally b.touch each other internally c.intersect at two points d.none of these

The two circles x ^(2)+y^(2)-2x +22y +5=0 and x ^(2) + y^(2) +14 x+6y +k=0 intersect orthogonally provided k is equal to-