magnetic circuit

The dimensions of the complete magnetic circuit, of the transformer you are going to construct, are given in Fig. 11.

A magnetic field may be produced through a coil of wire by winding it on the magnetic circuit shown in Fig. 8.

If the magnetic circuit surrounds the windings, as indicated in Fig. 10, the transformer is said to be of the shell type.

When the U-shaped pieces are all in place, the magnetic circuit will have the form and dimensions shown in Fig. 11.

When one of these is present in the magnetic circuit the magnetism will flow through the metal.