Question

What happens to the strength of a magnet if it is broken down into two pieces?

Answer 1

If magnet is broken in two pieces , there will be two smaller magnets.

The strength of a magnet is related to its size. 

So, the two smaller magnets will be weaker than the one original magnet. 

However, the relationship may not be linear. 

So a needle shaped magnet may be weaker than a coin shaped magnet of equal mass.

Thus, the sum of your two broken magnets may in fact be stronger than the original.

Answer 2

the strength of the magnet does not change because in a magnet there are tiny magnets called domains which are attached together. Each one supports or reinforces the magnetic field. Therefore when cut in half each new piece acts as a new magnet with both south nd north poles.