Question

A metallic conductor is suspended perpendicular to the magnetic field of a horseshoe magnet. The conductor gets displaced towards the left when a current is passed through it. What will be the effect on displacement of conductor if the:

1. Current through the conductor is increased?
2. Horseshoe magnet is replaced by another stronger horseshoe magnet?
3. Direction of current through the conductor is reversed?

Answer 1

The displacement of the conductor depends on the magnetic force

F = B I L

1. The magnetic force is directly proportional to the magnitude of the current flowing through the conductor. Hence, if the current through the conductor is increased, the displacement of the conductor will also increase.
2. Replacing the magnet with a stronger one increases the magnetic field strength (B), which results in a larger magnetic force and greater displacement. Hence, if the horseshoe magnet is replaced by another stronger horseshoe magnet, the displacement of the conductor will increase.
3. The direction of force is dependent on the direction of current. Reversing the current reverses the direction of the force according to Fleming’s left-hand thumb rule, causing displacement in the opposite direction. Hence, if the direction of the current through the conductor is reversed, the conductor will be displaced to the right (in the opposite direction).