In the transmission line shown, the impedance $${Z_{in}}$$ (in ohms) between node A and the ground is

For a parallel plate transmission line, let v be the speed of propagation and Z be the characteristic impedance. Neglecting fringe effects, a redution of the spacing between the plates by a factor of two results in

A transmission line with a characteristic impedance of 100 $$\Omega $$ is used to match a 50 $$\Omega $$ section to a 200 $$\Omega $$ section. If the matching is to be done both at 429 MHz and 1 GHz, the tength of the transmission line can be approximately

A transmission line of characteristic impedance 50 $$\Omega $$ is terminated in a load impedance $$Z_L$$. The VSWR of the line is measured as 5 and the first of the voltage naxima in the line is observed at a distance of $$\lambda /4$$ from the load. The value of $$Z_L$$ is