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Force on a Current in a Magnetic Field

• A magnetic field exerts a force on a wire carrying current. If the wire is straight, the force is given by F = I L x B, where I is the current, L is a vector whose magnitude is the length of the wire, and whose direction is that of the current, and B is the magnetic field vector.
• A magnetic field also exerts a torque, on a current loop, given by I A B sin(theta), where I is the current in the loop, A is the loop area, B is the magnitude of the magnetic field, and theta is the angle between the magnetic field vector and the normal (perpendicular) to the plane of the loop.