Two particles of equal masses are revolving circular path of radius r1 and r2 respectively with the same period.

The ratio of their centripetal force is: ... ?

Explanation & answer:

F=mr (omega) ^2

Here period is the same, and masses are equal, so

m1=m2=m

omega1=omega2=omega

So

F1/F2 = m (r1) (omega) ^2/m (r2) (omega) ^2 = r1/r2

so the forces are proportional to their radii.