Fleming's Left-Hand Rule
Fleming's Left-Hand Rule helps determine the direction of force on a current-carrying conductor in a magnetic field. Stretch out your left hand with thumb, index, and middle finger mutually perpendicular to each other.
Thumb points in the direction of the Force (F).
Index finger points in the direction of the Magnetic Field (B).
Middle finger points in the direction of the Current (I).
Current: Right to Left (Middle finger)
Magnetic Field: Left to Right (Index finger)
Force: Upwards (Thumb)
The Science Behind Fleming's Left-Hand Rule
Fleming's Left-Hand Rule describes the direction of force experienced by a current-carrying conductor in a magnetic field:
- The force is always perpendicular to both the current direction and magnetic field direction.
- The magnitude of force is given by F = BILsinθ, where B is magnetic field strength, I is current, L is conductor length, and θ is the angle between current and field.
- This principle is fundamental to electric motors and many electromagnetic devices.
- The right-hand rule is used for generators (motion → current), while the left-hand rule is for motors (current → motion).
The direction of force can be calculated using the cross product: F = I(L × B)
Where:
F = Force vector
I = Current magnitude
L = Length vector (direction of current)
B = Magnetic field vector
