Magnetic field lines form in concentric circles around a cylindrical current-carrying conductor, such as a length of wire. The direction of such a magnetic field can be determined by using the "right hand grip rule" (see figure at right). The strength of the magnetic field decreases with distance from the wire. (For an infinite length wire the strength is inversely proportional to the distance.) Bending a current-carrying wire into a loop concentrates the magnetic field inside the loop while weakening it outside. Bending a wire into multiple closely spaced loops to form a coil or "solenoid" enhances this effect. A device so
Induction cooking Induction cooking Induction cooking heats a cooking vessel electrically by magnetic induction, instead of by radiation or thermal conduction from an electrical heating element, or from a flame. Because inductive heating directly heats the vessel, very rapid increases in temperature can be achieved, and changes in heat settings are instantaneous. In an induction cooktop ("induction hob" or "induction stove"), a coil of copper wire is placed under the cooking pot and an alternating electric current is passed through it. The resulting oscillating magnetic field induces an electrical current in the pot. This large eddy current flowing through the resistance of