Question

Summary on Flemming's rule

Answer 1

Do you mean Fleming’s left‑ and right‑hand rules used in electromagnetism (motors and generators)? If so, here’s a short summary — tell me if you want a diagram or worked example.

- Purpose
- Fleming’s left‑hand rule: predicts the direction of force (motion) on a current‑carrying conductor in a magnetic field — used for motors (motor effect).
- Fleming’s right‑hand rule: predicts the direction of induced current when a conductor moves in a magnetic field — used for generators (electromagnetic induction).

- Finger mapping (same labels for both hands)
- Thumb = Motion (or Force)
- First/Index finger = Magnetic Field (from North to South)
- Middle finger = Current (conventional current direction)

- How to use
- Left hand: align your index finger with the magnetic field and your middle finger with the current; your thumb then points in the direction of the force (motion) on the conductor.
- Right hand: align index finger with the magnetic field and thumb with the motion of the conductor; your middle finger will point in the direction of the induced current (or align index with field and middle with current to find thumb = motion).

- Physical basis
- These are mnemonic devices for the vector relationships given by the Lorentz force and Faraday’s law: the electromagnetic force on a charge is F = q(v × B), and a conductor moving in a magnetic field experiences an electromotive force that can drive current.

- Quick examples
- Motor: current flows through a wire in a magnetic field → use the left hand to find the resulting push (motion).
- Generator: a wire is moved through a magnetic field → use the right hand to find the direction of the induced current.

If you meant a different “Flemming’s rule” (legal, biological, or another field), tell me which one and I’ll summarize that instead.