Summary and Exam Tips for Magnetism
Magnetism is a subtopic of Magnetism and Electromagnetism, which falls under the subject Physics in the Edexcel IGCSE curriculum. Magnetism involves the magnetic force exerted by magnets on certain materials, including other magnets. Each magnet has two poles: North and South. These poles create a magnetic field that allows magnets to exert force over a distance. Objects that exhibit both attraction and repulsion are magnets, where like poles repel and unlike poles attract. Magnetic materials are always drawn to magnets, regardless of the pole. Magnetism can be induced in metals with magnetic properties by placing them near strong magnets or using methods like stroking with a magnet or passing direct current through a coil. Steel is hard to magnetize but retains magnetism permanently, while soft iron is easy to magnetize but temporary. The magnetic field is the area around a magnet where its force operates, with field lines pointing from North to South. The strength of the magnetic field decreases with distance. Techniques like using iron filings or plotting compasses can visualize magnetic field lines.
Exam Tips
- Visualize Magnetic Fields: When asked to display magnetic fields, ensure you show both the strength and direction by adding arrows pointing southward from the north pole.
- Field Line Spacing: Remember that as the distance from the magnet increases, the magnetic field lines should be drawn further apart to indicate weakening strength.
- Magnetization Methods: Be familiar with methods of magnetization, such as stroking with a magnet or using direct current in a coil, as these are common exam topics.
- Material Properties: Understand the differences between materials like steel and soft iron in terms of magnetization and retention, as this is crucial for answering related questions.
