ln `n(n>=3)` circles the centres of no three circles are collinear. If the number of the radical axes of the circles is equal to the number of the radical centres of the circles then `n^(2)-4n-5=`

Radical Axis Of Two Circles

Let there be n circles no three of which have collinear centres.If the total number of radical axes is equal to total number of possible radical centres,then possible value of n is

(i) The radical axis is perpendicular to the line joining the centres of the given circles.

(iii)If two circles cut a third circle orthogonally,then the radical axis of two circle will pass through the center of the third circle.

Radical center || Family OF circle

If the length of a chord of a circle is equal to that of the radius of the circle , then the angle subtended , in radians , at the centre of the circle by the chord is

STATEMENT-1 : If n circles (n ge 3) , no two circles are non-centric and no three centre are collinear and number of radical centre is equal to number of radical axes, then n = 5. and STATEMENT-2 : If no three centres are collinear and no two circles are concentric, then number of radical centre is ""^(n)C_(3) and number of radical axs is ""^(n)C_(2).

(a,c) and (b,c) are the centres of two circles whose radical axis is the y-axis.If the radius of the first circle is r then the diameter of the other circle is

A charge q coulomb moves in a circle at n revolution per second and the radius of the circle is r metre. Then magnetic feild at the centre of the circle is