These devices share their name with the Smale-Williams strange attractor, which is formed by an iterated map on the solid torus. In fluidic control systems, these devices name and toggle a type of valve that can be either “normally open” or “normally closed.” The (15[2])vector potential of (15[1])one of these devices only has a theta component. These devices name the rotational component of a Helmholtz decomposition, which is a vector (15[1]-5[3])field with zero (*) divergence. A toroid is a circular one (-5[1])of these devices used to confine plasmas (10[1])in tokamaks. Ampere’s law can be used to (10[1])show (10[1])that the (10[1])magnetic field in one of these (10[1])devices is (10[1])“mu-naught I N,” where N is (10[1])the number of (10[1])turns per unit length. For (10[1])10 points, name these coils of wire commonly used as inductors. ■END■ (10[1])