To confirm whether an unknown metal strip is a permanent magnet or just an ordinary iron piece, which of the…
To confirm whether an unknown metal strip is a permanent magnet or just an ordinary iron piece, which of the following is the only sure test?
Attraction towards the North pole of a test magnet
Attraction towards the South pole of a test magnet
Repulsion from one of the poles of a test magnet
Attraction of small iron filings to the strip
Solution
An ordinary iron piece is attracted by both poles of a magnet, but repulsion occurs only between two like magnetic poles. Hence, repulsion is the sure test of magnetism.