All concentric circles are..... to each other.

Form the differential equation of all concentric circles at the origin.

If radii of two concentric circles are 4 cm and 5 cm, then length of each chord of one circle which is tangent to the other circle, is

If radii of the two concentric circles are 15cm and 17cm, then the length of each chord of one circle which is tangent to other is: 8cm(b)16cm(c)30cm(d)17cm

Order of the differential equation of the family of all concentric circles centred at (h,k) is

The two circles touch each other if

In two concentric circles prove that all chords of the outer circle which touch the inner circle are of equal length.