Plotting magnetic lines of force using the Iron Fillings method

Let’s see how to plot magnetic lines of force using the Iron Fillings method.

• Place a sheet of paper on top of a bar magnet and sprinkle iron filings thinly and evenly onto the paper.
• Tap the paper gently with a pencil and the filings should form patterns showing the lines of force. (figures below)
• Each filing turns in the direction of the field when the paper is tapped.
• This method is quick but of no use for weak fields.