Mid-ocean ridges are formed at divergent plate boundaries, where two tectonic plates are moving apart.

It's not possible to name just two plates because there are many mid-ocean ridges throughout the world, each separating different pairs of plates.

For example:

* The Mid-Atlantic Ridge separates the North American and Eurasian plates in the north, and the South American and African plates in the south.

* The East Pacific Rise separates the Pacific and Nazca plates.

So, to answer your question properly, you'd need to specify which mid-ocean ridge you're interested in.