;if a hoop A is made of iron & hoop B of wood are pushed at same time down to an inclined plane. find velocity of both if height of plane is 1m?

With what force are they being pushed? Or are they going down the ramp only because of their own weight?

It makes a big difference.

If they are pushed, the lighter wooden hoop will go faster.

If they are going down becasue of their own weight, they will accelerate at the same rate. Only the hoop shape (mass distribution) matters.