Is trench an example of mid-Atlantic ridge?

No, a trench is not an example of the mid-Atlantic ridge. The mid-Atlantic ridge is a diverging tectonic plate boundary where new oceanic crust is formed, characterized by underwater volcanic activity. In contrast, trenches are typically found at converging boundaries, where one tectonic plate is subducted beneath another, leading to deep oceanic trenches like the Mariana Trench.