The radius of the path of an object in uniform circular motion is doubled the centripetal for needed if its speed remains the same is

The centripetal force is reduced by half.

Explanation:

Now the centripetal force that keeps an object in circulation motion is given as;

F = mv^2/r

Where m is mass of object, v is velocity, r is the raduis

Looking at the formula above,

If we double r, force will reduce by 1/2 since Force is inversely proportional to the raduis of the path of the motion.