Which of the following does not affect the magnetic properties of a magnet?
Painting
Heat
Hammering
Dropped from a height
Applying a layer of non magnetic material doesn't have any effect on the magnetic strength of a magnet, given the thickness of the layer is small.
Which of the following does not affect the magnetic properties of a material?
Does the size of a magnet affect its attractive properties?
Heating a magnet does not affect its magnetism.