Describe how a piece of iron can be magnetised by the single touch method.

One pole of a strong bar magnet is placed at one end of the iron bar and stroked along its whole length to the other end. The magnet is then lifted well clear and brought back to the starting point, and the process is repeated many times in the same direction. The end where the stroking finishes acquires a polarity opposite to that of the stroking pole.

No citable source has been recorded for this record. Treat it as practice material, not as fact.

Explanation

Magnetisation by an electric current is far more effective and is the usual method.