Chapter 8

Conducting planes in air at $z=0$ and $z=d$ carry surface currents of $\pm K_0{\mathbf{a}}_x\mathrm{A}/\mathrm{m}.(a)$ Find the energy stored in the magnetic field per unit length \((0

A coaxial cable has conductor radii $a$ and $b$, where \(a

Find the mutual inductance between two filaments forming circular rings of radii $a$ and $\mathrm{\Delta }a$, where $\mathrm{\Delta }a\ll a$. The field should be determined by approximate methods. The rings are coplanar and concentric.

Show that the external inductance per unit length of a two-wire transmission line carrying equal and opposite currents is approximately $(\mu /\pi )\ln (d/a)$ $\mathrm{H}/\mathrm{m}$, where $a$ is the radius of each wire and $d$ is the center-to-center wire spacing. On what basis is the approximation valid?