In Activity 12.7, how do we think the displacement of rod AB will be affected if (i) current in rod AB is increased; (ii) a stronger horse-shoe magnet is used; and (iii) length of the rod AB is increased?
If the current in rod AB is increased, the displacement of the rod will increase. This is because a greater current produces a larger force on the current-carrying conductor when placed in the magnetic field.
If a stronger horse-shoe magnet is used, the displacement of the rod will increase. A stronger magnet produces a stronger magnetic field, which exerts a greater force on the current-carrying rod.
If the length of the rod AB is increased, the displacement of the rod will increase. A longer conductor in the magnetic field experiences a greater force, leading to larger displacement.
Explanation
The textbook context explains that a force is exerted on a current-carrying conductor when placed in a magnetic field. The magnitude of this force (and hence the displacement) depends on three factors: the current flowing through the conductor, the strength of the magnetic field, and the length of the conductor in the field. When any of these factors increases, the force increases proportionally, resulting in greater displacement of the rod.