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
A Is for Atom A Is for Atom A Is for Atom is a 14-minute 1953 promotional animated short documentary film created by John Sutherland and sponsored by General Electric (GE). It is now in the public domain. The short explains what an atom is, how nuclear energy is released from certain kinds of atoms, the peacetime uses of nuclear power, and the by-products of nuclear fission. It is Sutherland's most-decorated film, having won numerous honors at film festivals. "A is for Atom" was re-released by General Electric in 1964. John Sutherland Studios was contracted by GE to modernize the film. Changes include included