The correct option is Fleming’s left-hand rule.
Explanation
When a current-carrying conductor is placed in an external magnetic field, it experiences a mechanical force (Lorentz force). The direction of this force depends on the direction of the current and the direction of the magnetic field.
- Fleming’s Left-Hand Rule: This rule is used to determine the direction of force acting on a current-carrying conductor in a magnetic field. It states that if the thumb, forefinger, and middle finger of the left hand are stretched mutually perpendicular to each other:
- The Forefinger represents the direction of the Magnetic Field.
- The Middle finger represents the direction of the Current.
- The Thumb points in the direction of the Force (or Motion).
- Right-Hand Thumb Rule: This rule is used to determine the direction of magnetic field lines around a straight current-carrying conductor, not the force on the conductor.
- Lenz’s Law: This law relates to electromagnetic induction and determines the direction of induced current, stating that it opposes the change in magnetic flux that produced it.
- Gauss’s Law: This is a fundamental law in electrostatics relating electric flux through a closed surface to the charge enclosed.
Key Takeaway: Fleming’s Left-Hand Rule is applicable to motors (finding the direction of force), whereas Fleming’s Right-Hand Rule is applicable to generators (finding the direction of induced current).