Question

A student fixes a white sheet of paper on a drawing board. he places a bar magnetin the centre and sprinkles some iron filings uniformly around the bar magnet. thenhe taps gently and observes that iron filings arrange themselves in a certain pattern.

(a) why do iron filings arrange themselves in a particular pattern?
(b) which physical quantity is indicated by the pattern of field lines around thebar magnet?
(c) state any two properties of magnetic field lines.

Answer 1

Iron filings arrange in a certain pattern around a bar magnet because they align along the magnetic field lines. This pattern visually represents the magnetic field. Two properties of these field lines are that they emerge from the north pole and enter at the south pole of a magnet and they never intersect.

Step-by-step explanation:

When a student sprinkles iron filings around a bar magnet on a white sheet of paper and taps gently, the iron filings arrange themselves in a certain pattern due to the influence of the magnetic field created by the bar magnet. The magnetic field is invisible, but it exerts a force on ferromagnetic materials like iron, causing the filings to align along the field lines. This results in a visible pattern which represents the magnetic field lines.

The physical quantity indicated by the pattern of field lines around the bar magnet is the magnetic field.

Two properties of magnetic field lines are:

1. Magnetic field lines emerge from the north pole of a magnet and enter at the south pole, indicating the direction of the field.
2. Field lines never cross each other, demonstrating that the direction of the magnetic field is unique at any point in space.