K323 / 2027

Chapter 18

Electromagnetism

A current produces a magnetic field and can experience a force in another magnetic field.

Keep current, field and force directions distinct, then use them to explain an observation or a turning coil.

Straight wires, solenoids, electromagnets, conductor and charged-beam forces, turning coils and the single-coil d.c. motor. For K323 (2027) / 6091 (2026).

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  1. Magnetic fields from currents

    Draw straight-wire and solenoid fields, then predict the effects of changing or reversing current.

  2. Using electromagnets

    Connect a controlled current and an iron core to lifting and a magnetic overcurrent trip.

  3. Magnetic force and its direction

    Use experiments and current/field directions to explain forces on a wire and a charged-particle beam.

  4. Why a current-carrying coil turns

    Find the forces on the two active sides and explain how current and turn count affect turning.

  5. The single-coil d.c. motor

    Trace the coil connections, half-turn current reversal and role of the soft-iron cylinder.