An initially unmagnetised steel spanner lies horizontally, with its ring end on the left and its open end on the right. A permanent magnet is placed to the left of the spanner. Its south pole faces the ring end and induces magnetism in the spanner. In each proposed change, the spanner remains inside the magnetic field.
Which change causes a north pole to form at the open end of the spanner?
Turn the magnet so its north pole faces the ring end.
Hold the north pole of a second magnet near the open end, keeping the first magnet in place.
Move the south pole of the magnet closer to the ring end.
Use a stronger magnet with its south pole facing the ring end.