MG-U2 · Motor effect

Unit scope

Lectures

MG-U2 · Motor effect

MG-04 · MG-U2 · Planned

Motor effect and Fleming’s left-hand rule

ScopeShared Higher
Difficulty3 / 4 · proposed
Time35–40 min · estimated
StatusPlanned

Learning objectives

Predict conductor-force direction; calculate force for a perpendicular conductor; identify factors controlling magnitude.

8463 §§4.7.2.2 / 8464 §§6.7.2.2

DfE single-science pp.41–42 / Combined pp.34–35. Evidence checked 30 September–1 October 2026. Skills: WS1.2; MS3b,3c,5b.

Needs firstMG-03,FM-01,EL-02

Explanation

The motor effect is a force on a current-carrying conductor in a magnetic field. Field, conventional current and force directions are mutually perpendicular in the standard setup. The supplied F = BIl relation assumes the conductor is perpendicular to the field.

Concepts, equations and units: F=BIl at 90°; N,T,A,m; left-hand field/current/force directions; conventional current.

Prediction, demonstration and game exercise

Predict, observe, explain

Reverse current and field separately; observe force reversal and compare two lengths.

Planned learner game exercise

Set current, field and wire length to move a cargo rail in a specified direction.

Independent practice

Three F/B/I/l calculations and two direction checks.

Original practice example · Shared Higher

A perpendicular wire has B = 0.20 T, I = 3.0 A and length 0.10 m in the field. Find force.

Show working and model answer

Working / reasoning

F = BIl = 0.20 × 3.0 × 0.10.

Answer

0.060 N.

Exit check and success criteria

Two calculations and both orientations correct; applicability condition stated.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Force always along current; use electron flow as conventional-current direction; same formula valid for parallel orientation.

Practical preparation

Optional teacher-led low-voltage motor-effect demo; no RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

MG-05 · MG-U2 · Planned

Electric motors

ScopeShared Higher
Difficulty3 / 4 · proposed
Time30–35 min · estimated
StatusPlanned

Learning objectives

Explain coil rotation through forces on opposite sides; connect electrical work to mechanical output.

8463 §§4.7.2.3 / 8464 §§6.7.2.3

DfE single-science pp.41–42 / Combined pp.34–35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,1.4,3.6.

Needs firstMG-04

Explanation

Forces on opposite sides of a current-carrying coil form a turning effect. The motor converts electrical work into mechanical output with some dissipation. A simple continuous DC motor reverses the relevant coil current as it turns so the turning effect continues.

Concepts, equations and units: Motor-effect forces and moments; N and N m qualitatively; split-ring role can support explanation but no extra motor design equations.

Prediction, demonstration and game exercise

Predict, observe, explain

Freeze a coil at several orientations and label opposite forces; show reversal for continuing rotation.

Planned learner game exercise

Repair coil polarity/contacts in a model motor then predict rotation on field reversal.

Independent practice

Annotated motor diagram and energy-transfer explanation.

Original practice example · Shared Higher

Why can a current-carrying coil rotate even though forces on opposite sides point oppositely?

Show working and model answer

Working / reasoning

The forces act on different sides of the pivot, so their moments can act in the same rotational direction.

Answer

Opposite forces form a turning effect on the coil rather than simply cancelling rotation.

Exit check and success criteria

Opposite-side forces give consistent turning direction and energy accounting includes surroundings.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Both sides feel the same-direction force; a motor creates energy; every motor turns continuously without commutation.

Practical preparation

Optional safe model motor demonstration; no RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

MG-06 · MG-U2 · Planned

Loudspeakers and headphones

ScopeSeparate Physics Higher
Difficulty3 / 4 · proposed
Time25–30 min · estimated
StatusPlanned

Learning objectives

Explain moving-coil conversion from changing current to pressure variations.

8463 §§4.7.2.4 / No Trilogy counterpart

DfE single-science pp.41–42 / Combined pp.34–35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,1.4,3.6; MS4a.

Needs firstMG-04,WA-06,EL-07

Explanation

A changing current in the loudspeaker coil produces a changing force in its magnetic field. The coil and cone vibrate, making pressure variations in air. Pitch follows oscillation frequency; increasing amplitude is a different change.

Concepts, equations and units: Motor effect; AC current A, frequency Hz; coil/cone displacement; no acoustic power formula.

Prediction, demonstration and game exercise

Predict, observe, explain

Show current trace, coil force and cone motion with consistent phase-labelled model.

Planned learner game exercise

Match electrical frequency to cone motion and sound-pressure waveform; diagnose reversed or missing components.

Independent practice

Explain a four-stage current→force→vibration→sound chain and interpret a waveform.

Original practice example · Separate Physics Higher

A loudspeaker is driven by an AC signal at 500 Hz in the model. What frequency is the cone’s driven oscillation?

Show working and model answer

Working / reasoning

The alternating force follows the drive signal; the model cone oscillates at the supplied drive frequency.

Answer

500 Hz.

Exit check and success criteria

All four links correct and sound frequency tied to drive frequency.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Sound carries the electrical current to the ear; loudspeakers use the generator effect; amplitude changes necessarily change pitch.

Practical preparation

Optional low-volume loudspeaker observation; no RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

Area capstone

Sources and full programme

Sources checked 30 September–1 October 2026. Specifications govern content; textbooks supplement it. England has no single prescribed Physics course book. The full planning document includes sourced comparisons of Collins separate Physics and Trilogy books, Hodder/Hachette Physics and Oxford Physics listings, with access/approval limitations.

Download the complete Markdown programme and coverage matrix

A subsection map is proposed coverage. Clause-level educator review, item moderation, model validation and hands-on provision remain release gates. No all-board alignment or exam-board endorsement is claimed.