In Activity 13.7, how do we think the displacement of rod AB will be affected if
(ii) a stronger horse-shoe magnet is used;
When a current-carrying wire is placed in the magnetic field, it experiences a force, this force is proportional to the length of wire, the strength of the magnetic field and current through the wire.
And hence When a stronger horse-shoe magnet has used the strength of the magnetic field is high, and it will experience a greater force and hence will be more displaced.