Question

Why Iron Filling Don't Get Stick To The Copper Wire Passing Through A Cardboard Sheet , Why They Get Aligned In Concentric Circles When Iron Fillings Were Sprinkled On It

Answer 1

Dear Student,
Here in this case when you pass current through a copper wire passing through a card board sheet then the iron fillings beside it gets aligned in the concentric circles rather than sticking to the copper wire .
Now why does it happen ?What is the physics behind it?
Look when an wire passes electric current through it self then a magnetic field is generated beside it which exerts a magnetic force in the region surrounding it . This force lines are arranged in concentric circles from north to south arranges the iron fillings in the pattern of concentric circles around the copper wire and does not stick to the copper wire .
Regards