An unmagnetized steel bar buried in earth in the north -south direction would, after a few days, exhibit magnetic properties, making it a weak magnet. Explain by giving reasons how this is possible. In what way will the effect be different if the steel bar is to be placed above the surface of earth ?

Explanation

What happens to an iron bar placed near a strong magnet? Compare an iron bar placed in a strong magnetic field with an iron bar placed in a weak magnetic field.