Skip to content
Physics notebook Cambridge IGCSE 0625

Topic 4 of 6 · 11 modules planned

Electricity and magnetism

Charge, current and circuits, magnets and the link between electricity and magnetism.

Modules

  1. Module 1 · syllabus 4.1

    Magnets and magnetic fields

    What is the invisible pattern around a magnet?

    This module is planned. It will have readings, an experiment, practice with self-checks and a final check.

Syllabus statements for this topic · for teachers · 88 statements

Core for every pupil · Supplement also for Extended entry. Paraphrased from the Cambridge IGCSE Physics 0625 syllabus (2026–2028); check the official syllabus for exact wording.

4.1 Simple phenomena of magnetism

  • 4.1.1Forces between poles and magnetic materialsC
  • 4.1.2Induced magnetismC
  • 4.1.3Temporary soft-iron versus permanent steel magnetsC
  • 4.1.4Magnetic versus non-magnetic materialsC
  • 4.1.5Magnetic field: region where a pole feels forceC
  • 4.1.6Field-line pattern and direction around a bar magnetC
  • 4.1.7Field direction: the force on a north poleC
  • 4.1.8Plotting field lines with compass or iron filingsC
  • 4.1.9Uses of permanent magnets and electromagnetsC
  • 4.1.10Magnetic forces from interacting fieldsS
  • 4.1.11Field-line spacing shows field strengthS

4.2.1 Electric charge

  • 4.2.1.1Positive and negative chargesC
  • 4.2.1.2Like charges repel, unlike charges attractC
  • 4.2.1.3Charging by friction and detecting chargeC
  • 4.2.1.4Friction charging moves only electronsC
  • 4.2.1.5Experiment separating electrical conductors from insulatorsC
  • 4.2.1.6Electron model of conductors and insulatorsC
  • 4.2.1.7Charge measured in coulombsS
  • 4.2.1.8Electric field: region where a charge feels forceS
  • 4.2.1.9Field direction: the force on a positive chargeS
  • 4.2.1.10Field patterns: point charge, sphere, parallel platesS

4.2.2 Electric current

  • 4.2.2.1Current is a flow of chargeC
  • 4.2.2.2Using analogue and digital ammeters and their rangesC
  • 4.2.2.3Conduction in metals by free electronsC
  • 4.2.2.4Direct versus alternating currentC
  • 4.2.2.5Current as charge per time; I = Q/tS
  • 4.2.2.6Conventional current versus electron flow directionS

4.2.3 Electromotive force and potential difference

  • 4.2.3.1E.m.f. as work per unit charge round a circuitC
  • 4.2.3.2E.m.f. measured in voltsC
  • 4.2.3.3P.d. as work per unit charge through a componentC
  • 4.2.3.4P.d. measured in voltsC
  • 4.2.3.5Using analogue and digital voltmeters and their rangesC
  • 4.2.3.6E = W/QS
  • 4.2.3.7V = W/QS

4.2.4 Resistance

  • 4.2.4.1Resistance R = V/IC
  • 4.2.4.2Measuring resistance with a voltmeter and ammeterC
  • 4.2.4.3Wire resistance with length and thickness, qualitativelyC
  • 4.2.4.4Current–voltage graphs: resistor, filament lamp, diodeS
  • 4.2.4.5Resistance proportional to length, inverse to areaS

4.2.5 Electrical energy and electrical power

  • 4.2.5.1Circuits carry energy from source to surroundingsC
  • 4.2.5.2Electrical power P = IVC
  • 4.2.5.3Electrical energy E = IVtC
  • 4.2.5.4Kilowatt-hours and the cost of electricityC

4.3.1 Circuit diagrams and circuit components

  • 4.3.1.1Drawing and reading circuit diagrams; component behaviourC
  • 4.3.1.2Diodes and LEDs in circuit diagramsS

4.3.2 Series and parallel circuits

  • 4.3.2.1Same current everywhere in a series circuitC
  • 4.3.2.2Building and using series and parallel circuitsC
  • 4.3.2.3Combined e.m.f. of cells in seriesC
  • 4.3.2.4Combined resistance in seriesC
  • 4.3.2.5Parallel: source current exceeds each branch currentC
  • 4.3.2.6Two parallel resistors: less than either aloneC
  • 4.3.2.7Why lighting circuits use parallel lampsC
  • 4.3.2.8Junction currents and p.d. rules in calculationsS
  • 4.3.2.9Current in equals current out at a junctionS
  • 4.3.2.10Calculating two resistors in parallelS

4.3.3 Action and use of circuit components

  • 4.3.3.1P.d. rises with resistance at constant currentC
  • 4.3.3.2How a variable potential divider worksS
  • 4.3.3.3Potential divider: R1/R2 = V1/V2S

4.4 Electrical safety

  • 4.4.1Hazards: damaged insulation, hot cables, damp, overloadingC
  • 4.4.2Live, neutral and earth wires; switch in liveC
  • 4.4.3Fuses and trip switches; choosing ratingsC
  • 4.4.4Earthed or double-insulated appliance casingsC
  • 4.4.5Fuse protection for double-insulated appliancesC

4.5.1 Electromagnetic induction

  • 4.5.1.1Moving conductor or changing field induces an e.m.f.C
  • 4.5.1.2Experiment demonstrating electromagnetic inductionC
  • 4.5.1.3Factors affecting the size of an induced e.m.f.C
  • 4.5.1.4Induced e.m.f. opposes the change causing itS
  • 4.5.1.5Relative directions of force, field and induced currentS

4.5.2 The a.c. generator

  • 4.5.2.1Simple a.c. generator; slip rings and brushesS
  • 4.5.2.2Generator e.m.f.–time graphs and coil positionS

4.5.3 Magnetic effect of a current

  • 4.5.3.1Field patterns of straight wires and solenoidsC
  • 4.5.3.2Experiment mapping fields of wires and solenoidsC
  • 4.5.3.3Relays and loudspeakers use the magnetic effectC
  • 4.5.3.4How field strength varies around wires and solenoidsS
  • 4.5.3.5Effect of current size and direction on the fieldS

4.5.4 Force on a current-carrying conductor

  • 4.5.4.1Experiment: force on a current in a fieldC
  • 4.5.4.2Relative directions of force, field and currentS
  • 4.5.4.3Force direction on charged-particle beams in a fieldS

4.5.5 The d.c. motor

  • 4.5.5.1Turning effect on a coil and what increases itC
  • 4.5.5.2Electric motor: split-ring commutator and brushesS

4.5.6 The transformer

  • 4.5.6.1Construction of a simple iron-cored transformerC
  • 4.5.6.2Primary, secondary, step-up and step-downC
  • 4.5.6.3Vp/Vs = Np/NsC
  • 4.5.6.4Transformers in high-voltage transmissionC
  • 4.5.6.5Advantages of high-voltage transmissionC
  • 4.5.6.6How a transformer worksS
  • 4.5.6.7Ideal transformer: IpVp = IsVsS
  • 4.5.6.8Cable losses P = I²R and high voltageS