State Fleming's left hand rule.

Fleming's left-hand rule is used to determine the direction of force acting on a current-carrying conductor placed in a magnetic field. It states:

Hold your left hand out flat with the thumb, index finger, and middle finger at right angles to each other.

• Thumb: Represents the direction of the force (or motion) acting on the conductor.
• Index finger: Represents the direction of the magnetic field (lines of force).
• Middle finger: Represents the direction of the current flowing through the conductor.

This rule only applies to conductors carrying a current and moving in a magnetic field. It does not describe the behaviour of a stationary charge in a magnetic field.