申論題

4.For a coaxial transmission line shown in Fig. 2, the capacitance per unit length isand the inductance per unit length is. At high frequencies, the intemal inductance drops off (that is, approaching 0, and you should know which term is the internal inductance).

(4%)(b)請問在地(Ground,即半徑b粗體部分)外的 magnetic flux density B值為何? The capacitance of a line charge of radius a over a ground O, as shown in Left of Fig. 3 C =.