Answer : 2. "Andre Marie Ampere "
Explanation :

1. French scientist Andre-Marie Ampère suggested that a magnet should also exert an equal and opposite force on a current-carrying conductor.

2. A current-carrying wire has its own magnetic field.

3. A current-carrying wire attracts a magnetic material like a normal bar magnet.

4. When the current is withdrawn or the switch is closed, there is no magnetic effect in that case.

5. This phenomenon was called the magnetic effect of current.