Exercise 6.2.6: The plasma in a fluorescent tube

Thirteen further exercises in the spirit of the problems, the worked examples and the home exercises, graded from easy to harder within each group. Exercises 6.2.1–6.2.3 are about lossy media and the loss tangent, Exercises 6.2.4–6.2.5 about good conductors and the skin effect, Exercises 6.2.6–6.2.8 about plasmas and the group velocity, and Exercises 6.2.9–6.2.13 come from the exercise lecture and mix all three. They use only the equations listed at the head of this subsection, together with $v_g=d\omega /d\beta$ and $\gamma {\eta }_c=\mathrm{j}\omega \mu$, $\gamma /{\eta }_c=\sigma +\mathrm{j}\omega \epsilon$.