This topic summary covers Topic Summary: The Motor Effect within The Motor Effect for GCSE Physics. Revise The Motor Effect in Magnetism for GCSE Physics with 18 exam-style questions and 12 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 13 of 13 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 13 of 13
Practice
18 questions
Recall
12 flashcards
Topic Summary: The Motor Effect
Key Terms
- Motor effect: force on current-carrying conductor in magnetic field
- Fleming's Left-Hand Rule: thumb=force, 1st=field, 2nd=current
- Split-ring commutator: reverses current every half turn
- Brushes: connect supply to spinning coil
Key Facts
- Use LEFT hand for motor effect
- Force is max when current ⊥ field
- Force is zero when current ∥ field
- Commutator is essential for continuous rotation
- DC motor has 4 parts: coil, magnets, commutator, brushes
Key Equations
- F = BIL
- F in N, B in T, I in A, L in m
- Increase F: increase B, I, or L
- Reverse current → force reverses direction
Exam Tips
- Left hand for motors — FBI (Force, B-field, I-current)
- Commutator reverses current every half turn
- Max force when perpendicular, zero when parallel to field
- Reverse current or reverse field = force reverses