Page:Elementary lectures on electric discharges, waves and impulses, and other transients (Steinmetz 1911).djvu/26

are crowded together between the conductors, and the magnetic field consists of eccentric circles surrounding the conductors, as shown by the drawn lines in Fig. 9.

An electrostatic, or, as more properly called, dielectric field, issues from the conductors, that is, a dielectric flux passes between the conductors, which is measured by the number of lines of dielectric force ${\mathit {\Psi }}$. With a single conductor, the lines of dielectric force are radial straight lines, as shown dotted in Fig. 8. By the return conductor, they are crowded together between the conductors, and form arcs of circles, passing from conductor to return conductor, as shown dotted in Fig. 9.

Fig. 9.—Electric Field of Circuit.

The magnetic and the dielectric field of the conductors both are included in the term electric field, and are the two components of the electric field of the conductor.

8. The magnetic field or magnetic flux of the circuit, $\Phi$, is proportional to the current, i, with a proportionality factor, L, which is called the inductance of the circuit.

(1)

$\Phi =Li$.

The magnetic field represents stored energy $w$. To produce it, power, p, must therefore be supplied by the circuit. Since power is current times voltage,

(2)

$p=e'i$.