Solution:
Given,Length of one chord of a circle = 10cm.
Consider, AB the chord of circle O and OA is the radius of it where OA = x.
Consider POA,
.
If OP = 0, them x = 5 cm.
If OP ≠ 0, then x > 5 cm
So from equation (1), we get x ≥ 5.
Therefore, option 4 is correct.