A student placed a magnet on top of a plastic support in a bowl of water - AQA - GCSE Physics - Question 5 - 2020 - Paper 1

The piece of iron was attracted to the fixed magnet. This happens because iron is a ferromagnetic material and can become magnetized in the presence of a magnetic field.

1. Place the compass near one pole of the bar magnet. Observe the direction the compass needle points.
2. Mark this position on the paper.
3. Move the compass to this marked point and observe the needle again, marking the position.
4. Repeat this process, moving the compass and marking the points along the path around the magnet.
5. Join the marked points with smooth lines to represent the magnetic field lines, adding arrows from the north pole to the south pole.
6. Continue this process around the magnet, including areas above and below the bar magnet.

A - C - B

Using the formula for elastic potential energy: $E_e = 0.5 imes k imes x^2$ where: k = 200 , \text{N/m}, x = 0.040 , \text{m}, we calculate:

$E_e = 0.5 imes 200 imes (0.040)^2$ $E_e = 0.5 imes 200 imes 0.0016$ $E_e = 0.16 \, \text{J}$