The radius of the circle `ax^2 + (2a-3) y^2 - 4x - 7 = 0` is : (A) 1 (B) `5/3` (C) `4/3` (D) 3

Find'the centre and radius of the circle (i) x^(2) +y^(2) + 4x - 1 = 0 (ii) 2 x^(2) + 2y^(2) = 3x - 5y + 7

Find the centre and radius of the circle 3x^(2)+ 3y^(2) - 6x + 4y - 4 = 0

The minimum radius of the circle which is orthogonal with both the circles x^2+y^2-12 x+35=0 and x^2+y^2+4x+3=0 is (a) 4 (b) 3 (c) sqrt(15) (d) 1

The point from which the tangents to the circle x^2 + y^2 - 4x - 6y - 16 = 0, 3x^2 + 3y^2 - 18x + 9y + 6 = 0 and x^2 + y^2 - 8x - 3y + 24 = 0 are equal in length is : (A) (2/3, 4/17) (B) (51/5, 4/15) (C) (17/16, 4/15) (D) (5/4, 2/3)

Radius of the circle x^2+y^2+2x costheta+2y sin theta-8=0 is 1 2. 3 3. 2sqrt(3) 4. sqrt(10) 5. 2

The equation of the circle which touches the axes of coordinates and the line x/3+y/4=1 and whose center lies in the first quadrant is x^2+y^2-2c x-2c y+c^2=0 , where c is (a) 1 (b) 2 (c) 3 (d) 6

The equation of the circle which touches the axes of coordinates and the line x/3+y/4=1 and whose center lies in the first quadrant is x^2+y^2-2c x-2c y+c^2=0 , where c is (a) 1 (b) 2 (c) 3 (d) 6

The line 2x-y+1=0 is tangent to the circle at the point (2, 5) and the center of the circle lies on x-2y=4. The radius of the circle is (a) 3sqrt(5) (b) 5sqrt(3) (c) 2sqrt(5) (d) 5sqrt(2)

The equation of the tangent to the circle x^2+y^2=25 passing through (-2,11) is (a) 4x+3y=25 (b) 3x+4y=38 (c) 24 x-7y+125=0 (d) 7x+24 y=250

The radius of the circle in which the sphere x^(I2)+y^2+z^2+2z-2y-4z-19=0 is cut by the plane x+2y+2z+7=0 is a. 2 b. 3 c. 4 d. 1