Coaxial Cable Resonance
Due to reflection from the open circuit end, the impedance seen at the sending end can have an array of different values: -



And this is all purely due to the phase angle of the returning wave when it hits the sending end. For instance, if the applied frequency is such that the line is one complete wavelength, the line behaves like an open circuit at the sending end (depicted as a tuned parallel LC). This is also the case at half a wavelength of cable.

For a quarter wave line, the input impedance becomes a short circuit (depicted by a series L and C). Ditto at 3/4 of a wavelength. In between those notable points the line can look inductive or capacitive. Purely down to how the returning wave interacts (on a phase angle basis) with the sending end voltage.