Question

what are the two ways in which you can trace the magnetic field pattern of a bar magnet

Answer 1

The two ways to trace the magnetic field of a bar magnet is by a compass and by iron filings in the compass needle method, you need to let the needle rotate freely and trace it.

In another way, you need to give the iron filings make the magnetic path for you.

Answer 2

You can also use tracing paper to first trace your embroidery pattern, then redraw the lines with the iron on pen/pencil on the back. Make sure you're drawing on the back of the pattern, otherwise your design will be reversed when you flip it to iron it onto the fabric.