The correct option is Maxwell’s corkscrew rule.
Explanation
In electromagnetism, the direction of magnetic field lines generated by a straight current-carrying conductor is determined by the relationship between the direction of the electric current and the resulting magnetic flux. This relationship is established through specific mnemonic rules.
Analysis of the Rule:
- Maxwell’s Corkscrew Rule: This rule states that if a right-handed corkscrew is rotated so that it advances in the direction of the conventional current, the direction of rotation of the handle represents the direction of the magnetic field lines. This is functionally identical to the Right-Hand Thumb Rule, where the thumb points in the direction of the current and the curled fingers indicate the magnetic field direction.
- Fleming’s Right-Hand Rule: This rule is distinct and is used to determine the direction of induced current in a conductor moving through a magnetic field (applicable to electric generators).
- Biot-Savart Law: This is a mathematical law used to calculate the magnitude and direction of the magnetic field produced by a current element. While it governs the physics, it is not the alternative name for the mnemonic rule itself.
- Lorentz Transformation: This concept belongs to the theory of special relativity, dealing with time and space coordinates, and is unrelated to determining magnetic field direction in this context.
Key Takeaway: Maxwell’s Corkscrew Rule is the alternative name for the Right-Hand Thumb Rule; both are used to find the direction of the magnetic field around a current-carrying conductor.