Simple question help needed please

Feb 2017
Firstly can I appologies for asking such a simple question, I last 'studied' physics thirty years ago at school and that was at a pre GCSE level and I was by no means a scholar.

Would one get a stronger magnetic 'pull' from a magnet if the ferrous metal it was attracted to was larger in size? In other words, I know the stronger the magnet the stronger the 'pull', but would a great mass of ferrous metal increase the pull as well?

Apologies for the daft question, thank you in advance.


PHF Helper
Jun 2010
Morristown, NJ USA
Not a daft question at all. If considering a magnet being attracted to a metal sheet, there is a correlation between the size of the metal sheet and the resulting magnetic force. Make the sheet metal area larger and the pull gets stronger, up to a point - once the sheet metal gets to be about 2 or 3 times the surface area of the magnet the effect diminishes, because the strength of the magnetic field diminishes with distance. So if you have a magnet with surface area of, say, 1 square inch, it will be attracted to a piece of metal with areas around 2 or 3 square inches just about as strongly as to a piece of metal with area 20 square inches.