Making a magnet, and destroying one

Material

How magnetised is the bar?

0 clips

The tiny magnets inside point every way in an unmagnetised bar. Line them up and the ends become poles.

Make a magnet

Switch on the coil and its field lines the tiny magnets up. When the current stops, soft iron lets go and steel holds on: that is the syllabus idea of temporary and permanent magnets.

Beyond the syllabus Hammering in the Earth's field, and stroking with the magnet (drag it along the bar, one direction, lift it clear to go back), also work.

Destroy a magnet Beyond the syllabus

Heat it: 20 °C

Above about 770 °C (the Curie temperature of iron) the tiny magnets are shaken out of line. These methods are not examined in 0625, but they show what magnetism inside a bar really is.

About this lab: Making a magnet, and destroying one

Magnetise soft iron or steel with a coil and see which keeps its magnetism. Stroking, hammering, a.c. and heating go beyond the syllabus.

IGCSE Physics 0625, topic 4.1, simulation 2 of 4. A model to think with, not the exam answer.

Making a magnet, and destroying one is a free, browser-based simulation for Cambridge IGCSE Physics 0625 (topic 4 Electricity and magnetism, section 4.1 Simple phenomena of magnetism). The course is assessed in Papers 1 and 2 (multiple choice), 3 and 4 (theory), 5 (practical test) and 6 (alternative to practical). There are 0 tabs, each a self-contained experiment with its own controls and live readings, and nothing to install: it runs on a laptop, tablet or classroom projector.

Syllabus coverage

4.1 Describe the forces between magnetic poles and between magnets and magnetic materials, including the use of the terms north pole (N pole), south pole (S pole), attraction and repulsion, magnetised and unmagnetised

4.1 Describe induced magnetism

4.1 State the differences between the properties of temporary magnets (made of soft iron) and the properties of permanent magnets (made of steel)

4.1 State the difference between magnetic and non-magnetic materials

4.1 Describe a magnetic field as a region in which a magnetic pole experiences a force

4.1 Draw the pattern and direction of magnetic field lines around a bar magnet

4.1 State that the direction of a magnetic field at a point is the direction of the force on the N pole of a magnet at that point

4.1 Describe the plotting of magnetic field lines with a compass or iron filings and the use of a compass to determine the direction of the magnetic field

Lessons on this topic: Magnetic poles, attraction, and repulsion, Temporary (soft iron) vs permanent (steel) magnets, Magnetic fields: drawing field lines and using a compass.

How to use this simulation

Use the controls beside the stage to change the set-up and read the live values.

The buttons at the end of the tab strip give the scene the whole window (Full screen, Hide controls) and, on a dark stage, a projector-friendly palette (Light scene). Many scenes also have drag handles: drag them to change the set-up directly.