Determining the current and voltage maxima on a Lecher line

In the experiment P3.7.3.1, a Lecher line open at the wire ends and a shorted Lecher line are investigated. The waves are reflected at the ends of the wires, so that standing waves are formed. The current is zero at the open end, while the voltage is zero at the shorted end. The current and voltage are shifted by l/4 with respect to each other, i. e. the wave antinodes of the voltage coincide with the wave nodes of the current. The voltage maxima are located using a probe with an attached incandescent lamp. An induction loop with connected incandescent lamp is used to detect the current maxima. The wavelength l is determined from the intervals d between the current maxima or voltage maxima. We can say