Electromagnetism joins electric current and magnetic fields. Two ideas carry most of it: a current in a field feels a force, and a changing field induces a voltage.
This cluster is part of SPM Physics. It builds on electricity, because currents, voltages and power appear in every lesson.
How do the lessons connect?
- Determining magnetic-force direction gives the motor effect.
- Explaining electromagnetic induction gives the reverse effect.
- Comparing motors and generators puts both into machines.
- Calculating transformer relationships uses induction between two coils.
- Explaining transmission losses shows why transformers matter for the power grid.
How do one magnet and one coil show the main ideas?
Push a magnet into a coil connected to a meter. The pointer kicks, and the faster you push, the bigger the kick. That is induction, and a coil with a moving magnet is a simple generator.
Now pass a current through the coil while it sits in a magnet’s field. The coil feels a force and turns, which is the motor effect. A transformer uses induction too: the changing current in one coil makes a changing field, and that induces a voltage in a second coil.
Who should start where?
If you mix up force and induction, begin with lessons 1 and 2. If you are comfortable with both but lose marks on calculations, go to lesson 4. Test the cluster with the practice set.
Use the timed original practice session builder when you want a timed attempt. For a teacher to work through your diagrams with you, see online one-to-one Physics tuition or the one-hour trial class (from RM50).